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Determining chemical composition of the silicate garnets using Raman spectroscopy

by

Rachel R Henderson

A Prepublication Manuscript Submitted to the Faculty of the

DEPARTMENT OF GEOSCIENCES

In Partial Fulfillment of the Requirements for the Degree of

MASTER OF SCIENCE

In the Graduate College

THE UNIVERSITY OF ARIZONA 2009

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Determining chemical composition of the silicate garnets using Raman spectroscopy

R.R. Henderson1 and R.T. Downs1 1 RRUFF Project, Department of Geosciences, University of Arizona, Gould-Simpson

Building #77, 1040 E 4th St., Tucson, AZ 85721

Abstract

The silicate garnets are a group of minerals with diverse chemical compositions and multifaceted impacts on the geological sciences. The determination of a silicate garnet’s chemical composition is typically done using electron microprobe or mass spectrometry, both of which are destructive. Raman spectroscopy has been used in the past century to identify crystalline materials by observing the vibrational modes.

This project created a technique which correlates the Raman modes of a silicate garnet and its chemical composition. This study utilizes forty silicate garnets, taken from RRUFF project samples, whose chemistry was determined by electron microprobe, and whose Raman spectra were measured using a Thermo Nikolet Almega microRaman system or an open access custom built Raman spectroscopic instrument. A correlation matrix was created to compare the shifts of Raman peak position and correlated changes in chemical composition. This approach can characterize silicate garnet samples with thirteen chemical compositional variations using six Raman modes. This method is accurate to within 5% of the electron microprobe calculation of bulk chemical composition, and correctly names all varietals of silicate garnet. This technique will make it possible for the future determination of chemical compositions of garnets to be non-destructive, thus advancing the utility of Raman spectroscopy, and making the estimation of chemical composition in the silicate garnet group much faster and easier than with the use of microprobe analysis. Introduction

The determination of accurate and precise chemical compositions for silicate garnets is useful for many scientific inquiries (Meagher, 1980). The chemical composition of garnets has been investigated by multiple techniques, including electron microprobe, X-ray diffraction, mass spectrometry, wet chemistry, and even by optical microscopy. Many of these methods are destructive, expensive, and time-consuming. Raman spectroscopy offers an alternative that is fast and requires little sample preparation.

The silicate garnets are a group of minerals whose general formula is as follows:

X3Y2 (SiO4)3 where X represents a divalent eight coordinated cation in a dodecahedral site, Y represents a trivalent six coordinated cation in an octahedral site, and Si is in a four coordinated tetrahedral site. The samples in this study show minor substitutions for Si. For classification purposes the samples are divided into two distinct chemical groups the pyralspites (pyrope [Mg3Al2(SiO4)3], almandine [Fe3Al2(SiO4)3], spessartine [Mn3Al2(SiO4)3]) and the ugrandites (uvarovite [Ca3Cr2(SiO4)3], grossular [Ca3Al2(SiO4)3], andradite [Ca3Fe2(SiO4)3]). These mineral names are assigned by International Mineralogical Societies naming conventions. Common X-site cations include Ca, Mg, Fe+2, and Mn. Common Y-cations include Al, Fe+3, Cr, and Ti. Common

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substitutes for Si in tetrahedral coordination are Al, Fe+3, and Ti. Extensive crystal chemical information can be found in the studies by Novak and Gibbs (1971) and Merli et al (1995). In these investigations a “stability” field for X-site and Y-site cations was created to illustrate that certain cations were more likely to be found in natural silicate garnets than others due to structural constraints. From the Merli et al (1995) study it is clear that natural silicate garnets prefer to be either calcic or non-calcic. Intermediate calcic species are very rare in nature and therefore it is reasonable, given the plots represented in this study, to treat garnets as bimodal based on calcium content in the X-site. There is also extensive solid-solution between major species of garnet as has been examined by Ganguly and Kennedy (1974), Ganguly (1976), and Ungaretti (1995). These studies examined experimentally that for the two groups of garnets, calcic and aluminous, solid solution is thermodynamically favorable. They also address the miscibility gap between natural calcic and non-calcic garnets and found that intermediate calcic garnets can be synthesized.

Most early studies of the Raman spectra of garnets were focused on YAG or yttrium aluminum garnets (c.f. Hurrell et al, 1968) because of their important optical properties. In these studies the factor group analysis and mode assignments were determined. There are 25 Raman modes for the cubic garnets. Several subsequent studies have been undertaken on the geologically important silicate garnets, including Griffith (1969) and Moore et al (1971). Griffith (1969) studied the Raman spectra of the major rock-forming minerals in order to understand the effects of SiO4 condensation, examining orthosilicates and cyclosilicates. He claimed that the Raman intensities attributed “to (SiOn) groups are rather weak owing to the small degree of π-bonding in Si-O linkages; thus the Raman technique is unlikely to be useful for the identification of silicate minerals”. Moore et al (1971) examined six different silicate garnets, representing four garnet species, and found that while not all 25 of the predicted Raman modes were observed, nevertheless, variations due to chemistry were found, and mode assignments were transferred from the previously determined YAG studies.

Hofmeister and Chopelas (1991a, b) recorded Raman spectra of five species of near end-member silicate garnets with the purposes of computing thermodynamic properties such as heat capacity and entropy and completed a more comprehensive mode assignment than previously done. Pinet and Smith (1994) undertook a study of 52 natural aluminum garnets including grossular and samples along the pyrope-almandine and almandine-spessartine joins. They found that peak positions of various intense modes displayed quasi-linear trends with chemical composition. They observed bands which only appear when there is Ca present. These bands are located between 440 and 390 cm-1 and between 240 and 230cm-1. They are thought to be “chemical markers” for Ca. They found no correlation between the atomic masses of the dodecahedral cations and the Raman peak positions. However a strong linear trend was observed between unit cell parameter and position of the peak near 900 cm-1. They conclude, however, that there are “several big problems” in establishing a correlation between chemical composition and Raman spectra. Kolesov and Geiger (1998) examined six garnet species to evaluate chemical influences on external modes. They reported that the frequencies of the SiO4 rotational modes are greater than those of the SiO4 translational modes. It is important to note that the octahedral or Y cation occupies a center of inversion and therefore has no Raman stretching modes associated with the atom in that site (Hofmeister and Chopelas 1991a). However, this study shows that by using several modes one can to take into consideration the variations in the associated vibrations of the other cation sites that are impacted by the Y site cation.

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Recently, evaluations of the water content in garnets have been conducted by Arredondo and Rossman (2002), and Thomas et al (2008). Both of these studies utilized a number of garnets with various amounts of hydrous component in order to determine if Raman spectroscopy can be used to determine water content in nominally anhydrous materials. Arredondo and Rossman (2002) found that OH content vary relatively smoothly in grossular but show no good correlation in spessartine-almandine. Thus, they concluded that Raman spectroscopy was not a good method for determining the OH composition in garnets. In contrast, however, Thomas et al (2008) demonstrated that Fe-content affects the Raman spectra, and that in non Fe-bearing garnets Raman is useful in determining the OH component.

Several investigations have been conducted to determine a correlation between garnet localities and diamonds. One such study done by Wang et al (1991) investigated the use of Raman spectroscopy to analyze pyrope inclusions in diamonds to determine if there were microstructral variations which indicate the presence of a hydrous component, thus proving the existence of water very deep in the earth. Manoun et al (2001) examined the Raman spectra of kimberlitic garnets to evaluate their usefulness as a probe of chemistry in order to determine the possible P-T regime in which diamond formation occurs. The study proposed the idea that Raman spectroscopy could be the sole technique needed to determine P-T history, and chemical composition in garnets. They found that a clear correlation exists between cell edge and Raman frequency variations and chemical composition, most clearly that of Ca and Cr content. They assumed that a change in chemical composition is correlated with a change in unit cell length, which is then correlated with a shift in Raman peak positions. However, this assumption is faulty because a given cell edge does not imply a unique chemical composition. They concluded that “ The extension of this study to other garnet compositions…is required to ascertain the possibility to apply Raman spectroscopy as a tool to identify different types of pyrope-rich garnets without additional need for other micro-analytical techniques.”

The possibility of using Raman spectroscopy to determine the chemical composition of minerals is intriguing and there have been other studies that attempted to correlate chemical composition within vibrational peak positions. For instance, Huang et al (2000) and Wang et al (2001) correlated Raman peak positions with the Ca, Mg and Fe-content of pyroxenes. Huang et al (2000) found the peaks that showed the greatest variation in position as a function of Fe-content, and used their positions as independent linear estimators of chemistry, with reported errors of 3% and 6% for iron in ortho- and clinopyroxene, respectively. Wang et al (2001) used the positions of only two Raman peaks to establish a two parameter equation that gave Mg/(Ca+Mg+Fe) and Ca/(Ca+Mg+Fe) ratios simultaneously, with a reported accuracy of 10%. Both of these methods require the investigator to have some prior knowledge of which crystal system of pyroxene one is investigating. They only can calculate the variations in calcium and magnesium ratios in pyroxenes. Both of these method limit investigators by requiring an alternate method of identification by X-ray diffraction or microprobe analysis, as inspection alone will not shed light on if one has an ortho- or clinopyroxene. Likewise these methods require some prior knowledge of chemical composition. Also by limiting the investigation of the Raman spectra to the variations in one peak it is difficult to accurately determine minor compositional variations. These studies only investigated major element compositions without accounting for minor M1 or M2 cation sites.

In this paper we will examine the correlation between chemical composition and Raman peak positions for the natural silicate garnets. We will not restrict ourselves to a small subset of chemical compositions, but will include fifteen measured major and minor chemical components

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found by electron microprobe analyses in our suite of 40 samples. We will show that not only was Griffith (1969) incorrect in his assertion that silicates could not be identified by Raman spectroscopy, but we will also show that it is possible to obtain precise chemical compositions from analysis of the Raman spectra. Experimental Methods

Samples of varying compositions were obtained through the RRUFF project (Downs, 2006). These samples represent compositions of all major garnet group members including pyrope (Mg3Al2(SiO4)3), spessartine (Mn+23Al2(SiO4)3), uvarovite (Ca3Cr+32(SiO4)3), almandine (Fe+23Al2(SiO4)3), andradite (Ca3Fe+32(SiO4)3), and grossular (Ca3Al2(SiO4)3). We chose samples that differ in color, morphology and physical characteristics in order to encompass many variations of natural garnet. By using a variety of chemistries the study was able to take into account silicate garnets of almost every possible chemical composition. Table 1 contains a list of the samples, along with their names (according to IMA conventions), RRUFF number, unit cell edge, and measured chemical formula from microprobe analysis. X-ray diffraction was performed on all samples in order to determine unit cell parameters, and guarantee proper identification. Two different instruments were used: (1) a Bruker D8 ADVANCE X-ray powder diffractometer with Cu radiation. Data were collected from 5˚≤ 2θ≤ 90˚ at intervals of .01˚ for 2 s/step. Samples were prepared as a slurry mount on PMMA slides. All reflections were indexed on the basis of a cubic Ia3d unit-cell, and cell parameters were refined using the software CrystalSleuth (Laetsch et al, 2006). (2) A Bruker X8 APEX2 CCD X-ray single-crystal diffractometer equipped with graphite-monochromatized MoKα radiation was used for those samples where there was an insufficient amount for powder measurements. Data were collected for 144 frames of 0.5° width in ω and 10 s counting time per frame. The total number of diffraction spots used to determine the cell parameters was 220 for sample R060326 and 732 for sample R060099. The large number of reflections ensured that the cell parameters from the single crystal machine were of comparable quality to those determined by the powder method. The refined cell parameters are listed in Table 1.

Chemical analyses were performed on a CAMECA SX50 Electron Microprobe using the standards listed in Table 2. Data were collected at 15-20 spots under conditions of 15 kV, 20 nA with a 1 to 2 μm spot beam. From these 15-20 spots an average measured chemical composition was calculated they are listed in Table 1. These spots were taken at a wide variety of locations in each crystal to ensure a bulk composition of each garnet, as there were some samples which exhibited minor compositional zoning. The details of each individual chemical calculation including original microprobe measurements are found in Appendix 1.

Raman spectra of the samples were collected from crystals of unknown orientation at 150 mW on a Thermo Almega microRaman system, using 532 and 780 nm solid-state lasers with a thermoelectric cooled CCD detector. The laser is partially polarized with ~4 cm–1 resolution and a spot size of 1 μm. Some Raman spectra were also collected from crystals oriented along the a-cell edge on a custom-designed optical bench with a 514 nm Argon ion laser, with a spot size of approximately 50 μm. Utilizing a 1200 grooves mm-1 grating centered at 452 nm, the spectra were acquired using WinSpec software. The specific polarization alignment was parallel to one of the other two crystallographic axes. Raman scattering was collected in the backscattered geometry. The Raman spot sizes are relatively small and were not used to measure specific zones in a mineral, however if close inspection and mapping was done this technique could easily be used to characterize zones inside a garnet as the spot sizes are very small.

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We determined that there are six unambiguous Raman peaks common to all our garnet spectra. Garnet has 25 possible Raman vibrations based on theoretical calculation. For this study we use only those peaks that are easy to locate and well defined in all 40 garnet samples. These peaks are defined as follows with associate mode assignments as presented in Hofmeister and Chopelas, (1991a):

peak 1(p1) is located between 980 and 1050 cm-1 This peak is often low in intensity and is associated with the v3 (T2g+T1u) vibration

peak 2 (p2) is located between 870 and 920 cm-1 This peak is often high in intensity especially in non-calcic garnets and is associated with the v1 (A1g) vibration

peak 3 (p3) is located between 810 and 870 cm-1 This peak is directly adjacent but lower in energy than peak 2 and is associated with the v3 (T2g+T1u) vibration

peak 4 (p4) is located between 600 and 650 cm-1 This peak is often very low in intensity and is associated with the v4 (T2g+T1u) vibration

peak 5 (p5) is located between 510 and 560 cm-1 This peak is moderate in intensity and is associated with the v2 (A1g) vibration

peak 6 (p6) is located between 340 and 375 cm-1 This peak is high in intensity especially in calcic garnets and is associated with the R(SiO4) (A1g) vibration

Using the CrystalSleuth software (Laetsch et al, 2006), these six peak positions were measured for each spectrum by fitting with a Pseudo-Voigt singlet function. Table 3 contains a list of the fitted peak positions for each sample. Plots of the spectra are background corrected and normalized for peak height comparison, and are presented in the Appendix. Selected spectra are shown in Fig. 1and peaks are identified using dotted lines.

8 Figure 1: These Raman spectra represent those study samples that are closest to the end-member compositions almandine, pyrope, spessartine, andradite, uvarovite and grossular. They have been background corrected and normalized for peak intensity. The six peaks with which we estimate chemical composition are shown by dashed lines and are labled p1-p6. They are grouped in order to illustrate the variations between calcic and non-calcic garnets. They are stacked to show the clear variations in peak position as a result of chemical variations. Note that these spectra have been normalized for peak height. For illustration of all 40 garnets in our study please refer to the appendix.

During the investigation of which Raman peaks to use it was discovered that the two most intense peaks in these spectra follow a trend. For calcic garnets (those with 50% or more calcium in the X-site) the most intense peak is p6 centered around 350 cm-1, where as in those garnets with less than 50% calcium the peak is p2 centered around 850 cm-1 is the most intense. This is illustrated in Figure 2 which shows the intensity ratio of these peaks (peak 6/peak 2) compared to the amount of Ca in the X-site. From this graph it is clear that a first order approximation as to which solid-solution a garnet falls is easy to ascertain from the ratio of these peaks. This also reinforces the idea presented by many scientists (Chmielova et al 1997, Merli et al 1995, and Manoun et al 2001) that the two major groups of garnets (pyralspites and ugrandites) are better characterized when treated separately.

Figure 2: This is a graph showing the ratio of peak 6 and peak 2 relative the amount of Ca in the X-site in fractional occupancy per site (calculated from microprobe data). Each sample is represented by one point on the graph. From this figure it is apparent that this ratio allows for a first order approximation of calcium content. These garnet compositions can then be classified in two separate groups. Those samples with 50% or greater Ca in the X-site were placed into a routine to solve for matrix XCa(Table 5) and those samples with less than 50% Ca in the X-site where place into the routine to solve for Xnon-Ca(Table 6).

More detailed sample information and extended scans and data for each sample can be

found on the web by visiting http://rruff.info/ or by using the sample number, for example http://rruff.info/R040001. These sample numbers are in Table 1.

Mathematical methods

Matrix methods were used to transform the thirteen chemical components of all forty silicate garnets to the six Raman peak positions through the equation:

C = XallP, where

C is a 13 × 40 matrix of chemical components based on fractional occupancy in each of the three distinct crystallographic sites, X, Y, and Z, with one sample per column. The data for this matrix are in Table 1.

http://rruff.info/�http://rruff.info/R040001�

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P is a 6 × 40 matrix of peak positions in Raman shift (cm-1), with one sample per column. The data for this matrix are in Table 3.

Xall is the 13 × 6 transformation matrix which correlates the 13 chemical components and 6 peak positions. It is determined by the following manipulations:

C = XallP CMt = XallPPt Xall = CPt(PPt)-1.

A FORTRAN computer program was written to handle the mathematical manipulations, and produce the values for the Xall-matrix (Table 4). Using the resulting Xall-matrix it is then possible to determine chemical composition of a silicate garnet sample given the known peak positions or vice versa. Due to the fact that the calcic and non-calcic garnets have very distinct differences in their Raman spectra, separate matrices were calculated for the Ca containing and non-Ca containing garnets using only those samples associated with each chemical group. This classification was made based on the reported microprobe chemical composition and reinforced by the variation in peak 6 to peak 2 ratios. We did not utilize the idea of “chemical markers” as reported in Pinet and Smith (1994). This classification and separation served to reduce errors and improve characterization of our samples. For garnets where Ca content is greater than 50% occupancy in the X-site:


P is a 6 × 22 matrix of peak positions in Raman shift (cm-1), with one sample per column. The data for this matrix are in Table 3.

XCa is the 12 × 6 transformation matrix which correlates the 12 chemical components and 6 peak positions. It is determined by the following manipulations:

C = XCaP CMt = XCaPPt XCa = CPt(PPt)-1

Values for XCa are reported in table 5. For garnets where Ca content is less than 50% occupancy in the X-site:


P is a 6 × 18 matrix of peak position in Raman shift (cm-1), with one sample per column. The data for this matrix are in Table 3.

Xnon-Ca is the 10 × 6 transformation matrix which correlates the 10 chemical components and 6 peak positions. It is determined by the following manipulations:

C = Xnon-CaP CMt = Xnon-CaPPt Xnon-Ca = CPt(PPt)-1.

Values for Xnon-Ca are reported in table 6.

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Results and Discussion Using this method each garnet’s chemistry can be estimated from its observed Raman

modes to within 6% average error in bulk composition of the sample when compared to that calculated according to the microprobe data (note that the intrinsic error associated with microprobe analysis is 2-3%). The study samples were separated into routines based on their calcium content, as calcic and non-calcic garnets have distinctly different Raman spectra as presented above. When separated into two routines the calcic and non-calcic garnets show reduced errors in bulk composition when compared to the bulk compositions calculated from microprobe data. The average error for the bulk composition of those garnets where Ca content is greater than 50% in the X-site is 3% and that for garnets containing less than 50% Ca was 5%. Fig. 3 shows histograms of the errors in bulk chemical composition calculated by each routine when compared to the calculation based on the electron microprobe data for each sample. Matrices for all these routines are provided in Tables 4(Xall), 5(XCa), and 6(Xnon-Ca). It should be noted that this mathematical procedure does not constrain values to positive numbers and this procedure may also produce percentage per site values that exceed one hundred percent. In these cases negative values should be treated as zeros, and values which exceed one hundred percent per site should be removed from the cation with the lowest overall value per site, likewise values which are less than one hundred percent should be added to the greatest calculated cation.

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Figure 3: (a) This histogram represents the frequencies of errors in bulk chemical composition as compared to microprobe calculations for all chemistries of silicate garnets represented by matrix Xall presented in Table 4 (b) This histogram represents the frequencies of errors in bulk chemical composition as compared to microprobe calculations for those garnets with exhibit less than 50% calcium content in their X-site represented by matrix Xnon-Ca presented in Table 6 (c) This histogram represents the frequencies of errors in bulk chemical composition as compared to microprobe calculations for those garnets with exhibit greater than 50% calcium content in their X-site represented by matrix XCa presented in Table 5

The routine correctly names all major varieties of garnet (according to IMA naming conventions) and shows a clear distinction between the calcic and non-calcic garnets. This conclusion shows that Raman spectroscopy can be used to estimating chemical composition in silicate garnets. This method can be used on very small sample sizes, for example our beam size is approximately 50 µm, and as a result Raman spectra could potentially even characterize specific zones inside a garnet(though it has not been attempted in this study). This technique will make naming and determining the chemical composition of silicate garnets becomes much less expensive and completely nondestructive. It also makes determining the chemical composition of a garnet much more mobile, because Raman spectroscopy can be utilized in very small spaces and handheld models are commercially available.

Several attempts to make a linear correlation between unit cell edge and chemical composition in garnets have been attempted using X-ray diffraction techniques (Chmielova et al 1997, and Merli et al 1995). Some have even correlated cell edge and changes in frequency of Raman modes (Manoun et al 2001). By correlating the Raman peak positions used in our study and cell edges for a wider variety of chemical composition, a plot similar to that presented in Manoun et al (2001) has been constructed (Fig. 4). A similar trend presented in Merli et al (1995), thus reinforcing the correlation between shifts in Raman modes and variations in unit cell edge as a result of changes in chemical composition. The trends found in this study also reinforce the idea that the differences in cell edge due to chemical composition encourage the treatment of the calcic and non-calcic garnets in two separate routines.

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Figure 4: This graph shows the correlation of the six previously reported peak positions and the a-cell edge as calculated from X-ray diffraction techniques. They appear in order from p1 down to p6. From this graph it is clear that there are two trends in a-cell edge vs. peak positions, the non-calcic garnets have lower reported unit cell edges where as the calcic garnets have larger cell edges.

One example of possible applications for this study is to characterize the chemical composition of garnet inclusions in diamonds. Fig. 5 shows Raman spectra of four garnet inclusions in a diamond taken using a Renishaw InVia machine, utilizing a 514nm laser (courtesy of Dr. Wuyi Wang of the Gemological Institute of America). The chemical composition of these garnets was calculated using matrix Xall presented in Table 4. From this calculation and the ratio of peak 6 and peak 2 it because clear that this was unlikely a calcic garnet. Therefore the compositions of these garnets were recalculated using matrix Xnon-Ca the results of which are presented in Table 7. These measurements required an adjustment to account for the pressure exhibited on the garnets by insitu measurements in the diamond. The garnets inside this diamond will be experiencing at most approximately 1 or 2 GPa of strain, though precise calculations are difficult without a 2D Raman tomography mapping of the inclusions (Nasdala et al 2005). The data that is presented at room pressure most closely matches pyrope, therefore it was adjusted according to Gillet et al 1992 using the reported values for variation in peak positions for pyrope with pressure for both 1 and 2 GPa (Table 7). This calculation subtracts the variation in peak position with pressure experienced by these samples, because these measurements are taken at room pressure and thus to account for a change in pressure inside the diamond one must shift peaks to lower frequency. It is observable from these calculations that changes in calcium content in the X-site and Y-site cations are not impacted by the slight variations which account for pressure changes. However, other X-site cations are greatly impacted by changes in shifts in Raman peaks associated with pressure changes. This sheds light on the application of this type of study for mantel derived garnets, and garnet inclusions in diamond and other mantel derived mediums.

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Figure 5: The above figure shows the Raman spectra from four garnet inclusions in diamond (provided by Dr. Wang). They have been background corrected and normalized for peak intensity. They all appear to have the similar peak position, and chemical compositions as presented in Table 7. This conclusion fits with the idea that all of these garnet inclusions were all likely derived from similar mantel locations.

This technique for determining the chemical composition of a mineral can be applied to other groups of isomorphic minerals in order to constrain the relationship of Raman mode shifts and chemical variations. By utilizing several Raman modes it is easier to constrain the relationships between several cation sites and correlating changes in chemical composition. Therefore it is clear that this method can certainly be applied to the pyroxene group minerals with consideration of crystal structure and it may prove more successful than the method proposed by Huang et al (2000) and Wang et al (2001) which only utilized the positions of two Raman peaks to establish a chemical variation. This method can also account for many variations in cations per site, which can expand the notion of pyroxene chemistry to include minor cation constituents or impurities.

It is also likely that this technique can be used in the future to examine zoning in minerals especially garnets. One would have to take Raman spectra in each suspected zone of a garnet and compare peak positions using the appropriate matrix. This may reduce the time and sample preparation needed to determine the P-T history of a metamorphic rocks.

This study illustrates that the proof of concept holds. It is possible to determine compositional variations in chemistry of an isomorphic group of minerals by Raman analytical techniques and a little matrix math. The assertion that “… the Raman technique is unlikely to be useful for the identification of silicate minerals” (Griffith, 1969) seems to have been misguided.

Acknowledgements This work was performed in collaboration with the RRUFF project and its contributors including Dr. Gelu Costin, Carla Eichler, Robert Dembowski, J Benjamin Rojas, Chen Li, and Dr. Hexiong Yang. Thanks also to Dr. Wang of the Gemological Institute of America for the impetus to investigate this idea and the use of his sample measurements.

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References Arrendondo E, Rossman G, (2002) Feasibility of determining the quantitative OH content of garnets with Raman spectroscopy,

American Mineralogist 87, 307-311 Chmielova M, Martinec P, Weiss Z, (1997) Almandine-pyrope-grossular garnets: a method for estimating their composition

using X-ray powder diffraction patterns, European Journal of Mineralogy 9,403-409 Downs R T (2006) The RRUFF Project: an integrated study of the chemistry, crystallography, Raman and infrared spectroscopy

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aluminian series pyrope-almandine-spessartine, Schweizerische Mineralogische und Petrographische Mitteilungen 74, 161-179

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Table 1. List of study sample mineral names, RRUFF number, unit cell edges and calculate chemical composition from microprobe analysis.

name RRUFF number

a-cell edge(Å) chemical formula calculated from electron microprobe analysis

Almandine R040076 11.5389(2) (Mg0.42 Ca0.11 Mn0.01 Fe0.46)3 Al2 (SiO4)3 Almandine R040079 11.5319(2) (Mg0.18 Ca0.06 Fe0.76)3 Al2 (SiO4)3 Almandine R040168 11.5837(1) (Ca0.02 Mn0.49 Fe0.49)3 Al2 (SiO4)3 Almandine R050029 11.5442(2) (Mg0.42 Ca0.12 Mn0.01 Fe0.45)3 Al2 (SiO4)3 Almandine R060099 11.5309(8) (Mg0.19 Ca0.08 Mn0.19 Fe0.64)3 (Al0.99 Fe0.01)2 (SiO4)3 Almandine R060450 11.5107(2) (Mg0.35 Ca0.01 Fe0.64)3 Al2 (SiO4)3 Almandine R070129 11.5291(2) (Mg0.20 Ca0.03 Mn0.03 Fe0.72)3 Al2 ((Si0.98 Al0.02)1O4)3 Andradite R040001 12.0630(2) Ca3 (Al0.02 Fe0.98)2 (SiO4)3 Andradite R050256 11.9411(2) (Ca0.76 Mn0.24)3 (Al0.33 Fe0.67)2 (SiO4)3 Andradite R050311 11.9779(8) (Ca0.96 Mn0.02 Fe0.02)3 (Al0.30 Fe0.69 Ti0.01)2 ((Si0.99 Al0.01)1O4)3 Andradite R060358 12.0587(2) Ca3 (Cr0.05 Fe0.95)2 (SiO4)3 Andradite R060326 12.037(2) (Ca0.99 Mn0.01)3 (Al0.10 Fe0.88 Ti0.02)2 (SiO4)3 Andradite R060423 11.9528(3) (Ca0.98 Mn0.01 Mg0.02)3 (Al0.50 Fe0.47 Ti0.03)2 ((Si0.98 Fe0.02)1O4)3 Andradite R060449 12.0646(2) Ca3 (Al0.03 Fe0.97)2 (SiO4)3 Grossular R040065 11.8517(2) (Ca0.97 Fe0.02 Mn0.01)3 (Al0.98 Fe0.01 Ti0.01)2 ((Si0.99 Al0.01)1O4)3 Grossular R040066 11.8665(2) (Ca0.97 Fe0.02 Mn0.01)3 (Al0.93 Fe0.07)2 (SiO4)3 Grossular R050036 11.8851(3) (Ca0.98 Mn0.02)3 (Al0.85 Fe0.15 Ti0.01)2 (SiO4)3 Grossular R050081 11.9740(4) (Ca0.97 Mg0.03)3 (Al0.51 Fe0.46 Ti0.31)2 ((Si0.98 Ti0.02)1O4)3 Grossular R050312 11.8701(2) Ca3 (Al0.88 Fe0.11 Ti0.01)2 ((Si0.99 Al0.01)1O4)3 Grossular R060278 11.9451(4) (Ca0.97 Mg0.02 Mn0.01)3 (Al0.60 Fe0.39 Ti0.01)2 ((Si0.99 Al0.01)1O4)3 Grossular R060382 11.8526(1) (Ca0.98 Mg0.01 Mn0.01)3 Al2 ((Si0.99 Ti0.01)1O4)3 Grossular R060442 11.8553(1) (Ca0.95 Fe0.05)3 (Al0.93 Fe0.07)2(SiO4)3 Grossular R060443 11.8636(1) (Ca0.97 Mg0.01 Mn0.01 Fe0.01)3 (Al0.93 Fe0.07)2 (SiO4)3 Grossular R060444 11.8579(2) (Ca0.99 Mn0.01)3 (Al0.92 Fe0.07 Ti0.01)2 ((Si0.99 Al0.01)1O4)3 Grossular R060452 11.8529(1) (Ca0.98 Mg0.01 Mn0.01)3 (Al0.96 Fe0.03 Ti0.01)2 ((Si0.99 Al0.01)1O4)3 Grossular R060453 11.8516(9) (Ca0.97 Mg0.02 Mn0.01)3 (Al0.98 Ti0.02)2 (SiO4)3 Grossular R060499 11.8882(2) (Ca0.97 Mg0.03)3 (Al0.89 Fe0.10 Ti0.01)2 (SiO4)3

Pyrope R040159 11.5350(1) (Mg0.72 Ca0.11 Mn0.01 Fe0.16)3 (Al0.93 Fe0.06 Ti0.01)2 ((Si0.99 Al0.01)1O4)3 Pyrope R050112 11.5306(1) (Mg0.50 Ca0.10 Mn0.01 Fe0.39)3 (Al0.99 Fe0.01)2 (SiO4)3 Pyrope R050113 11.5717(3) (Mg0.61 Ca0.01 Mn0.01 Fe0.37)3 (Al0.91 Fe0.09)2 (SiO4)3 Pyrope R050446 11.5411(7) (Mg0.64 Ca0.14 Fe0.22)3 Al2 (SiO4)3 Pyrope R060441 11.5399(2) (Mg0.61 Ca0.13 Mn0.01 Fe0.25)3 (Al0.97 Cr0.03)2 (SiO4)3 Pyrope R060445 11.4941(1) (Mg0.61 Ca0.02 Mn0.01 Fe0.36)3 Al2 (SiO4)3 Pyrope R060448 11.5268(1) (Mg0.49 Ca0.07 Mn0.01 Fe0.43)3 Al2 (SiO4)3

Spessartine R060177 11.6505(3) (Mn0.95 Ca0.01 Fe0.04 )3 Al2(SiO4)3 Spessartine R060279 11.6798(3) (Mn0.55 Ca0.27 Fe0.15 Mg0.03 )3 (Al0.99 Fe0.01)2(SiO4)3 Spessartine R060447 11.6205(2) (Mn0.95 Ca0.01 Fe0.02 Mg0.01 )3 Al2(SiO4)3 Spessartine R060451 11.5892(1) (Mn0.42 Ca0.12 Fe0.13 Mg0.33 )3 Al2(SiO4)3 Uvarovite R060477 11.9320(1) Ca3 (Cr0.58 Al0.41 Ti0.02)2 ((Si0.99 Al0.01)1O4)3 Uvarovite R061041 11.9433(3) (Ca0.98 Mg0.02)3 (Cr0.62 Fe0.02 Al0.36 Ti0.01)2 (SiO4)3

16

Table 2. Standards used to measure electron microprobe calculations for all samples.

Chemical Mineral standard

Na: Albite Si: Diopside

Mg: Diopside Ca: Diopside Si: Pyrope

Mg: Pyrope Al: Pyrope Al: Anorthite K: K-Feldspar P: Apatite

Mn: Rhodonite Fe: Fayalite Cr: Chromite Ti: Rutile1 Zn: Willemite Zr: ZrO2-synthetic

17

Table 3: Sample name, RRUFF number, and measured peak positions for all six peaks used in the study.

Sample name RRUFF number p1(cm-1) p2(cm-1) p3(cm-1) p4(cm-1) p5(cm-1) p6(cm-1)

Almandine R040076 1023.7 918.9 867.4 641.4 559.8 357.5 Almandine R040079 1045.1 921.1 866.6 636.9 559.3 350.6 Almandine R040168 1040.4 912.3 860.2 630.3 554.0 346.8 Almandine R050029 1044.2 917.4 862.8 638.1 557.9 355.9 Almandine R060099 1041.3 915.1 859.8 631.1 553.8 345.7 Almandine R060450 1047.9 920.7 866.6 638.1 558.5 350.5 Almandine R070129 1041.0 916.3 865.7 636.6 555.9 345.4 Andradite R040001 995.2 875.4 816.8 621.4 515.9 352.7 Andradite R050256 1000.2 883.5 823.4 606.6 526.7 368.5 Andradite R050311 998.0 877.9 819.9 600.7 524.4 369.7 Andradite R060358 995.8 875.6 818.9 610.1 517.3 352.9 Andradite R060326 993.5 873.4 815.5 600.7 516.1 367.3 Andradite R060423 994.6 875.6 821.2 648.5 532.6 370.9 Andradite R060449 995.8 873.4 816.6 604.2 514.9 369.7 Grossular R040065 1007.6 880.8 826.1 629.8 549.7 374.7 Grossular R040066 1005.9 879.7 824.8 625.2 544.7 373.4 Grossular R050036 1001.7 878.0 823.2 627.6 545.9 376.2 Grossular R050081 983.8 877.9 835.9 613.6 531.9 372.9 Grossular R050312 1002.8 879.4 823.7 621.9 544.6 370.9 Grossular R060278 996.2 875.9 820.3 614.9 548.1 369.7 Grossular R060382 1016.1 879.6 822.9 630.9 549.1 373.4 Grossular R060442 1005.4 878.8 823.3 626.5 545.8 372.3 Grossular R060443 1007.2 879.6 827.5 627.5 547.9 374.5 Grossular R060444 1002.1 879.9 825.6 626.5 548.1 372.3 Grossular R060452 1006.1 880.7 822.9 630.9 549.1 374.5 Grossular R060453 1006.1 880.7 826.4 626.3 549.1 373.4 Grossular R060499 1000.5 877.3 822.9 627.5 545.6 374.6

Pyrope R040159 1050.4 918.3 861.5 642.4 558.3 362.0 Pyrope R050112 1045.9 919.2 863.8 640.4 558.9 356.3 Pyrope R050113 1032.8 912.1 868.2 629.1 553.6 344.8 Pyrope R050446 1052.9 922.2 866.9 641.6 559.2 355.7 Pyrope R060441 1047.9 919.2 862.4 643.2 559.9 361.1 Pyrope R060445 1052.5 918.5 863.9 639.8 558.8 353.9 Pyrope R060448 1047.0 920.2 866.2 641.0 560.1 356.3

Spessartine R060177 1021.9 908.3 867.6 624.4 544.2 351.0 Spessartine R060279 1026.7 907.0 846.2 634.2 554.0 358.9 Spessartine R060447 1029.1 907.3 851.5 630.9 554.0 351.6 Spessartine R060451 1037.7 912.5 854.9 639.0 557.7 358.2 Uvarovite R060477 1001.9 892.6 831.2 620.1 533.3 371.6 Uvarovite R061041 100.6 892.7 838.8 621.4 532.7 371.9

18

Table 4. Matrix for all garnet chemical compositions. Xall chemistry

0.00462 -0.00435 0.00243 -0.00117 0.00174 -0.00806 -0.00223 0.00156 -0.00629 0.00503 -0.0101 0.02506 -0.00072 0.00481 -0.00266 -0.00159 0.00347 -0.00589 -0.00134 -0.00178 0.00679 -0.00208 0.00425 -0.00993 -0.00389 -0.00178 -0.00878 -0.00003 0.03376 -0.01293 0.00911 0.00172 0.00227 0.00037 -0.03089 0.01125 -0.00461 0.00037 0.00654 -0.0003 -0.00339 0.00258 -0.00039 -0.00005 0.00042 0.00018 -0.00021 0.00027 0.00052 0.0002 0.00057 -0.00061 -0.00043 0.00118 -0.00003 0.00006 -0.00006 -0.00012 0.00017 0.00005 -0.00008 -0.00001 0.00001 0.00031 -0.00017 -0.00005 -0.00013 -0.00007 0.00022 -0.00003 0 0.00008 0.00002 0.00007 -0.00041 0.00068 -0.00021 -0.00013

Table 5. Matrix for garnet chemical compositions with greater than 50% in the X-site. XCa

-0.00065 -0.0002 0.00064 0.00002 0.00033 0.00033 0.00317 -0.00771 0.00619 0.00105 -0.0013 -0.00131 -0.00238 0.00862 -0.00642 -0.00078 0.00051 0.00088 0.00052 -0.00078 0.00022 -0.0002 0.00012 0.00012 0.00442 -0.03254 0.01111 0.00203 0.02413 0.00388 0.01849 -0.0034 0.0032 -0.00267 -0.02779 -0.00338 -0.02173 0.03586 -0.0139 0.00047 0.00357 -0.00128 -0.0009 0.00068 -0.00007 0.00029 -0.00023 0.00083 0.00014 0.00309 -0.0021 -0.00058 0.00008 0.0005 -0.00036 0.00093 -0.00066 -0.00012 0.00036 -0.00006 -0.00026 0.00043 -0.00044 0.0004 -0.00026 0.00036 0.00027 -0.0013 0.00119 -0.0001 -0.0001 0.00002 0.00088 -0.00323 0.00263 0.0005 -0.00042 -0.00079

Table 6. Matrix for garnet chemical compositions with less than 50% in the X-site. Xnon-Ca

0.00846 -0.00051 -0.01075 0.03266 -0.03119 -0.00617 -0.0016 0.00043 -0.00864 0.00846 0.00537 0.0012

-0.00183 -0.00106 0.03067 -0.0949 0.02283 0.06896 -0.00479 0.00109 -0.00981 0.05004 0.00468 -0.06127 -0.00092 -0.00044 -0.00001 0.00334 0.00165 -0.00195 0.0007 0.00028 0.00163 -0.00598 0.00046 0.00332

0.00022 0.00015 -0.00059 0.00104 -0.0007 -0.00035 0.00009 0.00001 0.00007 -0.00005 -0.00041 0.00027 0.00016 -0.00007 0.0014 -0.00368 0.0021 0.00245 -0.00007 0.00008 -0.0003 0.00202 -0.00111 -0.00116

19

Table 7. Measured peak positions for garnet inclusions in a diamond (provided by Dr. Wang GIA) and calculated chemical compositions based on 1 or 2 GPa pressure variations.

p1(cm-1) p2(cm-1) p3(cm-1) p4(cm-1) p5(cm-1) p6(cm-1) name Calculated Chemistry using Xnon-Ca

1044.6 914.9 859.3 638.4 557.2 355.9 11a (Mg0.42Ca0.11Mn0.16Fe0.31)3(Al0.99Fe0.01)2(SiO4)3

1042.4 911.5 855.5 636.4 554.7 353.3 11a (1GPa) (Mg0.47Ca0.11Fe0.40)3(Al0.99Fe0.01)2(SiO4)3






1041.7 912.3 855 636.2 555.1 353.6 18a (1GPa) (Mg0.45Ca0.12Fe0.43)3(Al0.99Fe0.01)2(SiO4)3

1039.5 908.9 851.2 634.2 552.6 351 18a (2GPa) (Mg0.50Ca0.12Fe0.38)3(Al0.99Fe0.01)2(SiO4)3


1041.2 911.5 855 637.4 554.2 354.2 23a (1GPa) (Mg0.51Ca0.12Fe0.37)3(Al0.99Fe0.01)2(SiO4)3

1039 908.1 851.2 635.4 551.7 351.6 23a (2GPa) (Mg0.56Ca0.12Fe0.32)3(Al0.99Fe0.01)2(SiO4)3

100 300 500 700 900 1100

Inte

nsit

y(ar

bitr

ary)

Raman shift (cm-1)

R040076

R040076

100 300 500 700 900 1100

Inte

nist

y(ar

bitr

ary)

Raman Shift(cm-1)

R040079

R040079

100 300 500 700 900 1100

Inte

nsit

y(ar

bitr

ary)

Raman shift(cm-1)

R040168

R040168

100 300 500 700 900 1100

Inte

nsit

y(ar

bitr

ary)

Raman shift(cm-1)

R050029

R050029

100 300 500 700 900 1100

Inte

nsit

y(ar

bitr

ary)

Raman shift(cm-1)

R060099

R060099

100 300 500 700 900 1100

Inte

nsit

y(ar

bitr

ary)

Raman shift(cm-1)

R060450

R060450

100 300 500 700 900 1100

Inte

nsit

y(ar

bitr

ary)

Raman shift(cm-1)

R070129

R070129

100 300 500 700 900 1100

Inte

nsit

y(ar

bitr

ary)

Raman shift(cm-1)

R040001

R040001

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R050256

R050256

100 300 500 700 900 1100

Inte

nsit

y(ar

bitr

ary)

Raman shift(cm-1)

R050311

R050311

100 300 500 700 900 1100

Inte

nsit

y(ar

bitr

ary)

Raman shift(cm-1)

R050377

R050377

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R060358

R060358

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R060326

R060326

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R060449

R060449

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R040065

R040065

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R040066

R040066

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R050036

R050036

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R050081

R050081

100 300 500 700 900 1100

inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R050312

R050312

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R060278

R060278

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R060382

R060382

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R060442

R060442

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

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)

Raman shift(cm-1)

R060443

R060443

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R060444

R060444

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R060452

R060452

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R060453

R060453

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R060499

R060499

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

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)

Raman shift(cm-1)

R060446

R060446

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

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)

Raman shift(cm-1)

R040159

R040159

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R050112

R050112

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

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)

Raman shift(cm-1)

R050113

R050113

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R050446

R050446

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R060441

R060441

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R060445

R060445

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R060448

R060448

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R060177

R060177

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R060279

R060279

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R060447

R060447

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R060451

R060451

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R060477

R060477

100 300 500 700 900 1100

Inte

nsit

y (a

rbit

rary

)

Raman shift(cm-1)

R061041

R061041

Electron Microprobe Data

Rruff ID: R040076 Mineral: AlmandineLocality: Barton Garnet mine, Gore Mountain, Warren County, New York, USA

Weight Percents

Analysis 8 11 13 14 15 16 17 18 19 20 Average StDevSiO2 40.26 40.48 40.21 39.97 40.13 39.98 40.08 39.97 39.72 40.52 40.13 0.25TiO2 0.04 0.03 0.04 0.07 0.04 0.07 0.08 0.06 0.07 0.06 0.06 0.02Al2O3 22.93 22.39 22.29 22.67 22.95 22.75 22.65 22.74 22.76 22.77 22.69 0.21FeO 21.74 21.95 21.78 22.14 21.87 22.11 22.08 22.08 21.98 22.14 21.99 0.15MnO 0.53 0.45 0.56 0.52 0.48 0.48 0.54 0.47 0.46 0.48 0.50 0.04MgO 11.45 11.43 10.45 11.40 11.45 11.40 11.56 11.40 11.45 11.46 11.35 0.32CaO 4.08 4.14 4.08 4.05 4.09 4.12 4.05 4.08 4.11 4.10 4.09 0.03Total 101.03 100.87 99.41 100.82 101.01 100.91 101.04 100.80 100.55 101.53 100.80 0.55

Cation Numbers on the Basis of 12 Oxygens averagestdev in formulaSi 2.994 3.018 3.041 2.987 2.988 2.985 2.988 2.987 2.976 3.003 2.997 0.019 3.00Ti 0.002 0.002 0.002 0.004 0.002 0.004 0.004 0.003 0.004 0.003 0.003 0.001 traceAl 2.010 1.968 1.987 1.997 2.014 2.002 1.990 2.003 2.010 1.989 1.997 0.014 2.00Fe 1.352 1.369 1.377 1.384 1.362 1.380 1.376 1.380 1.377 1.372 1.373 0.010 1.38Mg 1.270 1.271 1.178 1.270 1.271 1.269 1.285 1.270 1.279 1.266 1.263 0.030 1.26Ca 0.325 0.331 0.331 0.324 0.326 0.330 0.323 0.327 0.330 0.326 0.327 0.003 0.33Mn 0.030 0.026 0.032 0.030 0.027 0.027 0.031 0.027 0.026 0.027 0.028 0.002 0.03

Cations 7.98 7.98 7.95 8.00 7.99 8.00 8.00 8.00 8.00 7.99 7.99 0.02

Ideal Chemistry: Fe3Al2(SiO4)3 CNISF*Calculated Chemistry: (Fe2+1.38Mg1.26Ca0.33Mn0.03)Σ=3Al2.00(Si1.00O4)3

Microprobe Calibration DataInstrument: Cameca SX50 Xtal El Line Pk(s) Bkg(s) Bkg(+) Bkg(-) StandardsSample Voltage: 15 kV TAP Na Ka 20 10 600 -600 Albite-CrAcceleration Current: 20 nA TAP Si Ka 20 10 600 -600 DiopsideBeam Size: Spot TAP Mg Ka 20 10 350 -600 DiopsideDate of Analysis: 12/22/04 TAP Al Ka 20 10 600 -600 Anorthite-S

PET K Ka 20 10 600 -600 K-spar-OR1PET Ca Ka 20 10 600 -600 DiopsidePET Mn Ka 20 10 600 -600 Rhodonite-791LIF Fe Ka 20 10 500 -500 FayaliteLIF Cr Ka 20 10 500 -500 Chromite-SLIF Ti Ka 20 10 500 -500 Rutile1

Rruff ID: R040079 Mineral: AlmandineLocality: Ontario, CanadaWeight PercentsAnalysis 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 139 140 Average StDevSiO2 37.28 37.72 37.85 38.03 37.91 37.93 37.55 37.94 38.23 38.22 37.86 37.96 38.03 37.66 37.79 37.60 37.65 37.89 37.84 0.24Al2O3 21.55 21.36 21.44 21.43 21.50 21.19 20.88 21.62 21.39 21.44 21.73 21.50 21.68 21.65 21.50 21.53 21.25 21.00 21.43 0.23FeO 34.52 34.23 34.54 34.35 34.44 34.53 34.60 34.15 34.14 34.34 34.15 34.04 34.75 34.09 33.93 34.29 34.60 34.55 34.35 0.23MgO 4.57 4.63 4.61 4.57 4.52 4.46 4.44 4.48 4.40 4.33 4.71 4.57 4.53 4.58 4.55 4.47 4.36 4.34 4.51 0.11CaO 2.14 2.07 2.03 2.15 2.09 2.15 2.13 2.14 2.10 2.16 2.01 2.12 1.89 2.06 2.05 2.15 2.09 2.18 2.09 0.07Total 100.07 100.00 100.47 100.53 100.46 100.26 99.60 100.33 100.25 100.48 100.46 100.20 100.89 100.04 99.83 100.03 99.95 99.95 100.21 0.31

average stdev in formulaSi 2.970 2.999 2.997 3.007 3.000 3.012 3.007 3.003 3.026 3.021 2.991 3.007 2.998 2.990 3.004 2.990 3.001 3.019 3.002 0.013 3.00AlVI 2.023 2.001 2.001 1.996 2.006 1.983 1.971 2.017 1.995 1.997 2.024 2.007 2.014 2.026 2.015 2.018 1.996 1.972 2.010 0.013 2.00Fe2+ 2.300 2.276 2.288 2.271 2.279 2.293 2.317 2.260 2.260 2.270 2.257 2.255 2.291 2.263 2.256 2.280 2.307 2.303 2.279 0.019 2.29Mg 0.543 0.549 0.545 0.539 0.534 0.527 0.530 0.528 0.519 0.510 0.555 0.540 0.533 0.543 0.540 0.529 0.518 0.515 0.533 0.012 0.53Ca 0.183 0.176 0.172 0.182 0.177 0.183 0.183 0.181 0.178 0.183 0.170 0.180 0.160 0.175 0.175 0.183 0.178 0.186 0.178 0.006 0.18Cations 8.02 8.00 8.00 8.00 8.00 8.00 8.01 7.99 7.98 7.98 8.00 7.99 8.00 8.00 7.99 8.00 8.00 7.99 8.00 0.01

Fe3Al2(SiO4)3Calculated Chemistry:

Microprobe Calibration DataInstrument: Cameca SX50 Xtal El Line Pk(s) Bkg(s) Bkg(+) Bkg(-)Sample Voltage: 15 kV TAP Na Ka 20 10 600 -600Acceleration Current: 20 nA TAP Si Ka 20 10 600 -600Beam Size: Spot TAP Mg Ka 20 10 350 -600Date of Analysis: 11/24/04 TAP Al Ka 20 10 600 -600

PET K Ka 20 10 600 -600PET Ca Ka 20 10 600 -600PET Mn Ka 20 10 600 -600LIF Fe Ka 20 10 500 -500LIF Cr Ka 20 10 500 -500LIF Ti Ka 20 10 500 -500

Diopside


Cation Numbers on the Basis of 12 Oxygens

Ideal Chemistry:

(Fe2+2.29Mg0.53Ca0.18)Σ=3Al2.00(Si1.00O4)3

Standards

Rutile1

Rhodonite-791FayaliteChromite-S

Albite-CrDiopsideDiopsideAnorthite-SK-spar-OR1

Rruff ID: R040168 Mineral: Almandine

Weight PercentsAnalysis #2 #3 #5 #6 #7 #8 #9 #10 #11 #12 #14 #17 #18 #19 Average StDevSiO2 35.32 35.29 35.13 35.59 35.18 35.27 35.72 35.32 35.80 35.60 35.85 35.71 35.58 35.44 35.49 0.24TiO2 0.07 0.04 0.11 0.03 0.09 0.02 0.09 0.09 0.08 0.04 0.02 0.02 0.08 0.01 0.06 0.03Al2O3 20.22 20.29 20.04 19.83 20.09 20.32 20.21 20.08 20.13 19.99 19.90 20.10 19.93 20.07 20.09 0.14FeO 21.43 21.45 21.67 21.58 21.41 21.33 21.55 21.77 21.61 21.12 21.27 21.56 21.58 20.91 21.45 0.23MnO 20.70 20.76 20.65 20.64 20.74 20.62 20.58 20.55 20.49 20.62 20.69 20.49 20.38 20.57 20.61 0.11CaO 0.67 0.72 0.71 0.69 0.73 0.72 0.76 0.73 0.73 0.68 0.71 0.74 0.74 0.75 0.72 0.03

Totals 98.41 98.55 98.31 98.36 98.24 98.28 98.91 98.54 98.84 98.05 98.44 98.62 98.29 97.75 98.40 0.30

Cation normalized to 12 O average stdev in formulaSi 2.97 2.97 2.96 3.00 2.97 2.97 2.99 2.97 2.99 3.00 3.01 2.99 2.99 2.99 2.98 0.02 3.00Ti 0.00 0.00 0.01 0.00 0.01 0.00 0.01 0.01 0.01 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00Al 2.00 2.01 1.99 1.97 2.00 2.02 1.99 1.99 1.98 1.98 1.97 1.99 1.98 2.00 1.99 0.01 2.00Fe2+ 1.49 1.49 1.51 1.46 1.49 1.48 1.48 1.51 1.48 1.45 1.44 1.47 1.48 1.45 1.48 0.02 1.48Mn 1.48 1.48 1.48 1.47 1.48 1.47 1.46 1.46 1.45 1.47 1.47 1.45 1.45 1.47 1.47 0.01 1.47Ca 0.06 0.07 0.06 0.06 0.07 0.07 0.07 0.07 0.07 0.06 0.06 0.07 0.07 0.07 0.06 0.00 0.05Cation 8.00 8.00 8.01 7.96 8.01 8.00 7.99 8.00 7.98 7.97 7.95 7.97 7.97 7.98 7.99 0.02 7.990

Fe2+3Al2(SiO4)3Calculated Chemistry:

Microprobe Calibration DataXtal El Line Pk(s) Bkg(s)Bkg(+)Bkg(-) Standards

Instrument: Cameca SX50 TAP Si Ka 20 10 600 -600 pyrope-sSample Voltage: 15 kV TAP Mg Ka 20 10 600 -600 pyrope-2Acceleration Current: 20 nA TAP Al Ka 20 10 600 -600 pyrope-2Beam Size: Spot PET Ca Ka 20 10 600 -600 wollastoniteDate of Analysis: 07/23/05 PET Mn Ka 20 10 600 -600 synspes

LIF Ti Ka 20 10 500 -500 Rutile1LIF Fe Ka 20 10 500 -500 Fayalite


Ideal Chemistry:

(Fe2+1.48Mn1.47Ca0.05)Σ=3Al2.00(Si1.000O4)3

Rruff ID: R050029 Mineral: AlmandineLocality: Barton Garnet mine, Gore Mountain, Warren County, New York, USAWeight PercentsAnalysis 1 2 3 4 6 9 11 13 14 16 17 18 19 20 121* 123* 124* Average StDevSiO2 39.74 40.57 40.04 39.57 40.47 40.13 40.16 40.27 40.24 40.27 40.83 40.29 40.88 40.41 40.10 39.04 40.15 40.19 0.44Al2O3 23.01 23.09 23.06 22.98 23.05 23.13 23.18 22.77 22.86 22.53 22.13 22.83 22.67 22.75 22.74 22.98 22.09 22.81 0.32FeO 21.41 21.38 21.48 21.50 21.49 21.52 21.61 21.24 21.59 21.60 21.02 21.54 21.19 21.39 21.16 21.28 21.50 21.41 0.17MnO 0.39 0.45 0.40 0.41 0.42 0.42 0.37 0.43 0.44 0.45 0.42 0.39 0.43 0.41 0.44 0.39 0.39 0.41 0.02MgO 11.34 11.36 11.22 11.46 11.20 11.49 11.36 11.02 11.17 10.83 10.67 11.18 10.94 10.89 11.52 11.41 11.40 11.20 0.25CaO 4.66 4.71 4.63 4.74 4.68 4.73 4.72 4.65 4.62 4.61 4.55 4.61 4.56 4.62 4.78 4.66 4.66 4.66 0.06Total 100.55 101.56 100.83 100.66 101.31 101.42 101.40 100.38 100.92 100.29 99.62 100.84 100.67 100.47 100.74 99.76 100.19 100.68 0.55

Cation Numbers on the Basis of 12 Oxygens ACN StDev in formulaSi 2.97 3.00 2.99 2.96 3.00 2.98 2.98 3.01 3.00 3.02 3.07 3.00 3.04 3.02 2.99 2.95 3.02 3.00 0.03 3.00Al 2.03 2.01 2.03 2.03 2.01 2.02 2.02 2.01 2.01 1.99 1.96 2.00 1.99 2.00 2.00 2.04 1.95 2.01 0.02 2.00Fe2+ 1.34 1.32 1.34 1.35 1.33 1.34 1.34 1.33 1.35 1.36 1.32 1.34 1.32 1.34 1.32 1.34 1.35 1.34 0.01 1.34Mg 1.26 1.25 1.25 1.28 1.24 1.27 1.26 1.23 1.24 1.21 1.20 1.24 1.21 1.21 1.28 1.28 1.28 1.25 0.03 1.26Ca 0.37 0.37 0.37 0.38 0.37 0.38 0.38 0.37 0.37 0.37 0.37 0.37 0.36 0.37 0.38 0.38 0.38 0.37 0.00 0.37Mn 0.03 0.03 0.03 0.03 0.03 0.03 0.02 0.03 0.03 0.03 0.03 0.02 0.03 0.03 0.03 0.03 0.03 0.03 0.00 0.03Cations 8.00 7.99 7.99 8.01 7.98 8.00 8.00 7.98 7.99 7.97 7.94 7.98 7.95 7.97 8.00 8.02 7.99 7.99 0.02 8.00

Fe3Al2(SiO4)3Calculated Chemistry: (Fe2+1 34Mg1 26Ca0 37Mn0 03)Σ=3(Al 1 00)2(Si1 00O4)3Instrument: Cameca SX50 Xtal El Line Pk(s) Bkg(s) Bkg(+) Bkg(-)Sample Voltage: 15 kV TAP Na Ka 20 10 0 -600Acceleration Current: 20 nA TAP Si Ka 20 10 300 -100Beam Size: Spot TAP Mg Ka 20 10 350 -600

TAP Al Ka 20 10 600 -800TAP F Ka 20 10 600 -600PET Cr Ka 20 10 500 -500PET Ti Ka 20 10 500 -500PET P Ka 20 10 600 -600PET Ca Ka 20 10 600 -600LIF Mn Ka 20 10 500 -500LIF Fe Ka 20 10 500 -500LIF Zn Ka 20 10 500 -500


Ideal Chemistry:

Microprobe Calibration DataStandardsAlbite-CrPyrope-2Pyrope-2

Date of Analysis: 7/23/2005 Anorthite-S6/29/2005 MgF2

Chromite-SRutile2

FayaliteWillemit-2

ApatiteDiopsideRhodonite-791

Rruff ID: R060099 Mineral: AlmandineLocality: Alaska, USA

WDS scan: Al,Si,Mg,Fe,Mn,CaWeight PercentsAnalysis #5 #8 #9 #10 #11 #12 #13 #14 #15 #16 #17 #19 #20 Average StDevMgO 4.96 4.94 4.89 4.81 4.83 4.82 4.69 4.68 4.57 4.69 4.54 4.79 4.91 4.78 0.14SiO2 37.10 36.76 36.79 37.07 37.29 36.67 37.19 37.38 36.92 36.88 37.37 37.31 37.88 37.12 0.33Al2O3 20.57 20.74 20.73 20.76 20.91 20.84 20.79 20.88 20.83 20.65 20.85 20.84 20.97 20.80 0.11CaO 2.85 2.91 2.82 2.91 2.87 2.85 2.87 2.84 2.79 2.91 2.93 2.90 2.89 2.87 0.04MnO 7.85 8.23 8.32 8.52 8.17 8.17 8.28 8.69 8.69 8.40 8.63 8.48 8.03 8.34 0.26FeO 24.84 24.84 24.96 24.75 24.92 24.87 24.39 25.00 24.72 24.94 24.35 24.50 24.59 24.74 0.22Totals 98.17 98.43 98.51 98.82 98.99 98.21 98.22 99.46 98.52 98.47 98.65 98.82 99.28 98.66 0.40

Cation Numbers on the Basis of 12 Oxygens ACN StDev NCN CNISF*Si 3.00 2.97 2.97 2.99 2.99 2.97 3.00 2.99 2.98 2.98 3.01 3.00 3.02 2.99 0.01 2.98 3.00Al 1.96 1.98 1.98 1.97 1.98 1.99 1.98 1.97 1.98 1.97 1.98 1.97 1.97 1.97 0.01 1.97 1.98Fe3+ 0.04 0.02 0.02 0.03 0.02 0.01 0.02 0.03 0.02 0.03 0.02 0.03 0.03 0.03 0.01 0.03 0.02Fe2+ 1.64 1.66 1.66 1.64 1.65 1.68 1.63 1.64 1.65 1.66 1.62 1.62 1.61 1.64 0.02 1.64 1.63Mg 0.60 0.60 0.59 0.58 0.58 0.58 0.56 0.56 0.55 0.57 0.54 0.57 0.58 0.57 0.02 0.57 0.57Mn 0.54 0.56 0.57 0.58 0.56 0.56 0.57 0.59 0.60 0.58 0.59 0.58 0.54 0.57 0.02 0.57 0.56Ca 0.25 0.25 0.24 0.25 0.25 0.25 0.25 0.24 0.24 0.25 0.25 0.25 0.25 0.25 0.00 0.25 0.24Totals 8.02 8.04 8.04 8.03 8.02 8.03 8.01 8.03 8.02 8.03 8.01 8.02 8.00 8.02 0.01 8.00

Fe2+3Al2(SiO4)3Calculated Chemistry:

Instrument: Cameca SX50Sample Voltage: 15 kVAcceleration Current: 20 nA Xtal El Line Pk(s) BkgBkg(+) Bkg(-) StandardsBeam Size: Spot TAP Mg Ka 20 10 450 -600 pyrope2Date of Analysis: TAP Si Ka 20 10 600 -600 pyrope2

TAP Al Ka 20 10 600 -600 pyrope2ACN: Average Number of Cations PET Ca Ka 20 10 600 -600 diopsideNCN: Normalized Cation Numbers =ACN* LIF Mn Ka 20 10 500 -500 synspesStDev: Standard Deviation LIF Fe Ka 20 10 500 -250 fayaliteCNISF* = cation numbers in structural formulae, charge balanced


Ideal Chemistry:

Microprobe Calibration Data

(Fe2+1.63Mg0.57Mn0.56Ca0.24)Σ=3(Al1.98Fe3+

0.02)Σ=2(Si1.00O4)3

Rruff ID: R060450 Mineral: AlmandineLocality: Canada

WDS scan: Si Al Mg Fe Mn Ca

Weight PercentsAnalysis #1 #2 #3 #4 #5 #7 #8 #9 #10 #11 #12 #13 Averag StandarDevMgO 9.09 8.94 9.07 8.94 9.03 9.12 8.97 9.01 9.07 9.00 8.98 8.96 9.01 0.06Al2O3 22.44 22.51 22.50 22.38 22.38 22.36 22.39 22.51 22.20 22.41 22.38 22.49 22.41 0.09SiO2 38.32 37.87 37.97 37.65 38.32 38.32 37.99 38.29 38.12 37.96 38.20 38.36 38.11 0.22CaO 0.48 0.48 0.48 0.52 0.51 0.52 0.51 0.46 0.49 0.47 0.48 0.50 0.49 0.02MnO 0.25 0.25 0.22 0.21 0.25 0.26 0.27 0.24 0.22 0.19 0.22 0.21 0.23 0.02FeO 30.08 29.65 29.95 29.82 29.82 29.68 29.72 29.73 29.83 29.69 29.71 29.76 29.79 0.12Totals 100.65 99.69 100.20 99.53 100.30 100.25 99.86 100.24 99.92 99.72 99.97 100.28 100.05 0.31

Cation Numbers on the Basis of 12 Oxygens ACN StDev CNISF*Si 2.95 2.94 2.94 2.94 2.96 2.96 2.95 2.96 2.96 2.95 2.96 2.96 2.95 0.01 3.00Al 2.04 2.06 2.05 2.06 2.04 2.04 2.05 2.05 2.03 2.05 2.04 2.05 2.05 0.01 2.00Fe 1.94 1.93 1.94 1.95 1.93 1.92 1.93 1.92 1.94 1.93 1.93 1.92 1.93 0.01 1.92Mg 1.04 1.04 1.05 1.04 1.04 1.05 1.04 1.04 1.05 1.04 1.04 1.03 1.04 0.01 1.03Ca 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.00 0.04Mn 0.02 0.02 0.02 0.01 0.02 0.02 0.02 0.02 0.01 0.01 0.02 0.01 0.02 0.00 0.01Totals 8.03 8.03 8.03 8.04 8.02 8.02 8.03 8.02 8.03 8.02 8.02 8.02 8.02 0.01 8.00

Fe2+3Al2(SiO4)3Calculated Chemistry: (Fe2+1.92Mg1.03Ca0.04Mn0.01)Σ=3Al2.00(Si1.00O4)3Instrument: Cameca SX50Sample Voltage: 15 kVAcceleration Current: 20 nA Xtal El Line Pk(s) Bkg(s) Bkg(+) Bkg(-) StandardsBeam Size: Spot TAP Si Ka 20 10 600 -600 diopsideDate of Analysis: TAP Mg Ka 20 10 600 -600 diopside

TAP Al Ka 20 10 600 -600 anor-hkACN: Average Number of Cations PET Ca Ka 20 10 600 -600 diopsideNCN: Normalized Cation Numbers =ACN* PET Mn Ka 20 10 600 -600 rhod-791StDev: Standard Deviation LIF Fe Ka 20 10 500 -350 fayaliteCNISF* = cation numbers in structural formulae, charge balanced


Ideal Chemistry:

Microprobe Calibration Data

Rruff ID: R070129 Mineral: AlmandineLocality: Wrangell, Wrangell Island, Wrangell-Petersburg Borough, Alaska, USA WDS scan: Si Mg Fe Mn Ca

Weight Percents

Analysis #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 #13 #14 #15 Average Standard DevSiO2 36.49 36.63 36.69 36.64 36.51 36.61 36.72 36.89 36.58 36.96 36.73 36.84 36.96 36.74 36.70 36.71 0.15TiO2 0.02 0.00 0.03 0.12 0.07 0.02 0.07 0.03 0.00 0.01 0.02 0.00 0.06 0.05 0.04 0.04 0.03 not in wds scanAl2O3 21.68 21.71 21.70 21.79 21.83 21.80 21.86 21.83 21.76 21.85 21.85 21.89 21.72 21.89 21.95 21.81 0.08Cr2O3 0.00 0.00 0.00 0.04 0.04 0.05 0.02 0.00 0.02 0.04 0.01 0.03 0.10 0.00 0.02 0.02 0.03 not in wds scanMgO 4.93 4.96 4.98 5.01 5.09 4.99 5.07 5.00 5.07 5.04 5.13 5.11 5.10 5.04 5.04 5.04 0.06CaO 0.97 1.00 0.96 0.97 0.97 1.00 1.00 0.98 0.97 0.98 1.00 1.02 0.99 0.97 0.97 0.98 0.02MnO 1.85 1.80 1.73 1.71 1.65 1.67 1.62 1.61 1.53 1.57 1.51 1.48 1.41 1.46 1.41 1.60 0.14FeO 33.39 32.67 33.12 33.54 33.58 33.38 33.33 33.34 33.19 33.20 34.01 33.73 33.43 33.54 33.50 33.40 0.30Na2O 0.02 0.02 0.04 0.04 0.03 0.03 0.02 0.04 0.02 0.04 0.03 0.02 0.02 0.02 0.03 0.03 0.01 not in wds scanK2O 0.00 0.00 0.01 0.00 0.00 0.01 0.00 0.01 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 not in wds scanTotals 99.35 98.80 99.26 99.87 99.74 99.56 99.72 99.73 99.14 99.69 100.31 100.13 99.79 99.71 99.65 99.63 0.38

Cation Numbers on the Basis of 12 Oxygens ACN StDev in formula (+) chargesSi 2.93 2.95 2.95 2.93 2.92 2.93 2.94 2.95 2.94 2.95 2.93 2.94 2.95 2.94 2.93 2.94 0.01 0.98 4.00 11.76IVAl 0.07 0.05 0.05 0.07 0.08 0.07 0.06 0.05 0.06 0.05 0.07 0.06 0.05 0.06 0.07 0.06 0.01 0.02 3.00 0.18VIAl 1.99 2.01 2.00 1.98 1.98 1.99 1.99 2.00 2.00 2.01 1.98 1.99 1.99 2.00 2.00 2.00 0.01 2.00 3.00 6.00Fe2 2.18 2.13 2.16 2.17 2.18 2.17 2.16 2.16 2.16 2.15 2.20 2.18 2.16 2.17 2.17 2.17 0.01 2.15 2.00 4.30Fe3 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.00 0.06 3.00 0.18Mg 0.59 0.60 0.60 0.60 0.61 0.60 0.61 0.60 0.61 0.60 0.61 0.61 0.61 0.60 0.60 0.60 0.01 0.60 2.00 1.20Mn 0.13 0.12 0.12 0.12 0.11 0.11 0.11 0.11 0.10 0.11 0.10 0.10 0.10 0.10 0.10 0.11 0.01 0.11 2.00 0.22Ca 0.08 0.09 0.08 0.08 0.08 0.09 0.09 0.08 0.08 0.08 0.09 0.09 0.09 0.08 0.08 0.08 0.00 0.08 2.00 0.16Totals 8.04 8.02 8.03 8.04 8.04 8.04 8.03 8.03 8.03 8.02 8.05 8.04 8.02 8.03 8.03 8.03 0.01 24.00

ideal Fe2+3Al2(SiO4)3measured (Fe2+2.15Mg0.60Mn0.11Fe

3+0.06Ca0.08)Σ=3Al2.00((Si0.98Al0.02)Σ=1O4)3

Instrument: Cameca SX50 Calibration dataSample Voltage: 15 kV Xtal El Line Pk(s) Bkg(s) Bkg(+) Bkg(-) StandardsAcceleration Current: 20 nA TAP Si Ka 20 10 600 -600 diopsideBeam Size: Spot TAP Na Ka 20 10 600 -600 albite-Cr

TAP Mg Ka 20 10 600 -600 diopsideTAP Al Ka 20 10 600 -600 anor-hkPET K Ka 20 10 600 -600 kspar-OR1PET Ca Ka 20 10 600 -600 diopsidePET Mn Ka 20 10 600 -600 rhod-791LIF Fe Ka 20 10 500 -500 fayaliteLIF Cr Ka 20 10 500 -500 chrom-sLIF Ti Ka 20 10 500 -500 rutile1


Electron Microprobe DataRruff ID: R040001 Mineral: AndraditeLocality: Stanley Butte, Graham County, Arizona, USA

Weight PercentsAnalysis 141 142 143 144 145 146 147 148 149 150 151 152 153 154 Average StDev

SiO2 34.95 34.98 35.17 34.88 35.13 34.60 34.56 34.77 34.63 34.41 35.48 34.84 34.67 34.65 34.84 0.29TiO2 0.00 0.00 0.05 0.00 0.00 0.03 0.05 0.07 0.00 0.01 0.00 0.04 0.00 0.04 0.02 0.03

Al2O3 0.69 0.12 0.22 0.16 0.14 0.33 0.33 0.96 0.99 0.42 0.12 0.68 0.17 0.67 0.43 0.31Cr2O3 0.00 0.01 0.04 0.00 0.00 0.00 0.00 0.01 0.00 0.01 0.01 0.01 0.00 0.03 0.01 0.01Fe2O3 30.36 31.05 30.57 30.56 30.83 30.58 30.29 29.84 29.61 30.55 30.64 30.52 31.19 30.09 30.48 0.43MnO 0.17 0.12 0.18 0.17 0.17 0.14 0.13 0.16 0.15 0.22 0.14 0.20 0.18 0.14 0.16 0.03MgO 0.03 0.03 0.02 0.02 0.02 0.03 0.04 0.02 0.03 0.02 0.04 0.03 0.00 0.03 0.03 0.01CaO 33.02 32.69 32.95 32.96 32.96 32.63 32.65 32.67 32.75 32.92 32.61 32.88 32.79 33.00 32.82 0.15

Total 99.22 99.01 99.18 98.75 99.25 98.33 98.04 98.50 98.16 98.57 99.03 99.20 98.99 98.66 98.78 0.41

Cation Numbers on the Basis of 12 Oxygens ACN StDev NCN in formulaSi 2.976 2.989 2.997 2.989 2.994 2.977 2.981 2.976 2.975 2.959 3.023 2.969 2.969 2.968 2.982 0.016 2.978 3.00Ti 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000Al 0.069 0.012 0.022 0.017 0.014 0.034 0.033 0.097 0.100 0.043 0.012 0.068 0.017 0.068 0.043 0.031 0.043 0.04Cr 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

Fe3+ 1.940 2.000 1.960 1.970 1.980 1.980 1.960 1.920 1.910 1.970 1.960 1.950 2.010 1.940 1.961 0.028 1.958 1.96Mn 0.012 0.009 0.013 0.013 0.012 0.010 0.009 0.011 0.011 0.016 0.010 0.014 0.013 0.010 0.012 0.002 0.012 traceMg 0.004 0.004 0.003 0.002 0.003 0.003 0.005 0.003 0.004 0.003 0.005 0.003 0.000 0.004 0.003 0.001 0.003 0.00Ca 3.012 2.993 3.008 3.026 3.010 3.008 3.018 2.996 3.014 3.032 2.976 3.001 3.009 3.029 3.009 0.015 3.006 3.00

Cations 8.013 8.007 8.003 8.017 8.013 8.012 8.006 8.003 8.014 8.023 7.986 8.005 8.018 8.019 8.010 0.009 8.000

Calculated Chemistry:

Microprobe Calibration DataInstrument: Cameca SX50 Xtal El Line Pk(s) Bkg(s) Bkg(+) Bkg(-) StandardsSample Voltage: 15 kV TAP Na Ka 20 10 600 -600 Albite-CrAcceleration Current: 20 nA TAP Si Ka 20 10 600 -600 DiopsideBeam Size: Spot TAP Mg Ka 20 10 350 -600 DiopsideDate of Analysis: 11/24/04 TAP Al Ka 20 10 600 -600 Anorthite-S

PET K Ka 20 10 600 -600 K-spar-OR1ACN: Average Number of Cations PET Ca Ka 20 10 600 -600 DiopsideNCN: Normalized Cation Numbers =ACN*8/8.010 PET Mn Ka 20 10 600 -600 Rhodonite-791StDev: Standard Deviation LIF Fe Ka 20 10 500 -500 Fayalite

LIF Cr Ka 20 10 500 -500 Chromite-SLIF Ti Ka 20 10 500 -500 Rutile1

Ideal Chemistry: Ca3Fe2(Si O4)3Ca3(Fe 1.96Al 0.04)2(SiO4)3 ; trace amounts of Mn

Rruff ID: R050256 Mineral: AndraditeLocality: Franklin, Sussex County, New Jersey, USAWeight PercentsAnalysis 21 22 23 24 26 27 28 30 31 32 33 34 35 36 37 38 39 40 Average StDevSiO2 36.14 36.68 36.51 36.61 36.99 36.67 36.82 36.92 36.93 37.09 36.87 37.05 36.51 36.84 36.66 36.86 36.84 36.85 36.77 0.23TiO2 0.08 0.05 0.06 0.10 0.04 0.04 0.09 0.08 0.06 0.05 0.07 0.06 0.04 0.04 0.05 0.03 0.05 0.06 0.06 0.02Al2O3 5.88 5.86 5.69 5.59 6.79 6.80 6.69 7.05 6.77 6.63 6.65 6.60 6.83 6.64 6.60 6.72 6.63 6.66 6.50 0.43Fe2O3 21.41 21.41 21.65 21.80 19.83 19.90 20.33 19.56 19.99 20.66 20.43 20.19 20.07 20.57 20.02 20.43 20.23 20.07 20.48 0.66MnO 9.77 9.55 9.54 9.36 10.18 9.98 10.54 10.74 10.27 10.29 9.96 10.02 10.46 10.23 10.26 10.19 9.84 10.28 10.08 0.36CaO 25.70 25.69 25.63 25.80 25.50 25.58 25.20 25.11 25.45 25.72 25.57 25.50 25.37 25.45 25.51 25.39 25.39 25.43 25.50 0.18

Total 98.98 99.24 99.08 99.26 99.33 98.97 99.67 99.46 99.47 100.44 99.55 99.42 99.28 99.77 99.10 99.62 98.98 99.35 99.39 0.36

ACN StDev NCN CNISF*Si 3.00 3.02 3.02 3.02 3.03 3.02 3.02 3.02 3.03 3.02 3.02 3.04 3.00 3.02 3.02 3.02 3.03 3.03 3.02 0.01 3.02 1.00Al 0.59 0.59 0.57 0.56 0.67 0.68 0.66 0.70 0.67 0.65 0.66 0.66 0.68 0.66 0.66 0.67 0.66 0.66 0.65 0.04 0.65 0.33 Fe3+ 1.37 1.36 1.38 1.39 1.26 1.27 1.29 1.24 1.27 1.30 1.29 1.28 1.28 1.30 1.27 1.29 1.29 1.27 1.30 0.04 1.30 0.67Mn 0.71 0.69 0.69 0.67 0.73 0.72 0.75 0.77 0.73 0.73 0.71 0.72 0.75 0.73 0.74 0.73 0.71 0.74 0.72 0.02 0.72 0.24Ca 2.35 2.33 2.34 2.35 2.30 2.32 2.27 2.27 2.30 2.30 2.31 2.30 2.30 2.29 2.32 2.29 2.30 2.30 2.31 0.02 2.31 0.76Cations 8.01 7.99 7.99 7.99 8.00 8.00 8.00 8.00 8.00 8.00 7.99 7.99 8.01 8.00 8.00 7.99 7.99 7.99 8.00 0.01 8.00

Calculated Chemistry:Microprobe Calibration Data

Instrument: Cameca SX50 Xtal El Line Pk(s) Bkg(s) Bkg(+) Bkg(-)Sample Voltage: 15 kV TAP Na Ka 20 10 600 -600Acceleration Current: 20 nA TAP Si Ka 20 10 600 -600Beam Size: Spot TAP Mg Ka 20 10 350 -600Date of Analysis: 09/20/05 TAP Al Ka 20 10 600 -600

TAP F Ka 20 10 600 -600PET Cl Ka 20 10 500 -500

ACN: Average Number of Cations PET Ca Ka 20 10 600 -600PET Mn Ka 20 10 600 -600

StDev: Standard Deviation LIF Fe Ka 20 10 500 -500CNISF=Cation Numbers in structural formulae LIF Cr Ka 20 10 500 -500*=cations normalized for each structural site LIF Ti Ka 20 10 500 -500

NCN: Normalized Cation Numbers =ACN*8/7.999

MgF2Sodalite

Rhodonite-791FayaliteChromite-SRutile1

DiopsideAnorthite-S

Diopside

StandardsAlbite-CrDiopside



Ideal Chemistry:(Ca0.76Mn0.24)3(Fe

3+0.67Al0.33)2(SiO4)3

Ca3Fe2(Si O4)3

Rruff ID: R050311 Mineral: AndraditeLocality: Calaveras County, California, USAWeight PercentsAnalysis 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Average StDevSiO2 36.72 36.82 36.73 36.65 36.71 36.25 36.69 36.58 36.72 36.54 36.42 36.29 36.47 36.76 36.68 36.17 36.31 36.62 36.80 36.58 0.20TiO2 0.53 0.56 0.52 0.53 0.53 0.52 0.51 0.46 0.47 0.56 0.51 0.55 0.59 0.56 0.64 0.56 0.60 0.51 0.54 0.54 0.04Al2O3 6.19 6.14 6.23 6.21 6.18 6.28 6.14 6.25 6.32 5.96 6.12 5.95 5.69 5.90 6.11 5.85 5.57 6.08 5.91 6.06 0.20Fe2O3 22.95 22.63 23.45 23.12 23.05 23.63 23.83 23.41 23.55 23.41 23.93 24.12 24.42 23.91 23.17 23.51 24.19 23.60 23.50 23.55 0.45MnO 0.91 0.94 0.96 0.91 0.86 0.98 1.06 1.04 1.05 0.96 0.96 0.90 0.89 0.95 0.92 0.88 0.92 1.07 0.97 0.95 0.06CaO 32.62 32.67 32.69 32.78 32.71 32.00 32.11 32.24 32.01 32.45 32.18 32.11 32.38 32.28 32.81 32.55 32.02 32.35 32.50 32.39 0.28

Total 99.92 99.76 100.58 100.20 100.04 99.66 100.34 99.98 100.12 99.88 100.12 99.92 100.44 100.36 100.33 99.52 99.61 100.23 100.22 100.06 0.29

ACN StDev NCN CNISF*Si 2.99 3.00 2.98 2.98 2.99 2.96 2.98 2.98 2.98 2.98 2.97 2.96 2.97 2.99 2.98 2.97 2.98 2.98 2.99 2.98 0.01 2.97 1.00Ti 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.04 0.03 0.04 0.04 0.04 0.03 0.03 0.03 0.00 0.03 0.01Al 0.60 0.60 0.61 0.61 0.60 0.62 0.60 0.61 0.62 0.58 0.60 0.58 0.56 0.57 0.60 0.58 0.55 0.59 0.58 0.59 0.02 0.59 0.30Fe3+ 1.37 1.37 1.37 1.37 1.37 1.35 1.37 1.36 1.36 1.39 1.37 1.39 1.41 1.40 1.37 1.39 1.41 1.38 1.40 1.38 0.02 1.37 0.69Fe2+ 0.06 0.04 0.08 0.08 0.06 0.13 0.11 0.10 0.11 0.07 0.12 0.12 0.12 0.09 0.08 0.10 0.11 0.09 0.06 0.09 0.02 0.09 0.03Mn 0.06 0.07 0.07 0.06 0.06 0.07 0.07 0.07 0.07 0.07 0.07 0.06 0.06 0.07 0.07 0.06 0.07 0.08 0.07 0.07 0.00 0.07 0.02Ca 2.90 2.90 2.89 2.90 2.90 2.85 2.84 2.86 2.84 2.89 2.86 2.86 2.87 2.86 2.91 2.91 2.86 2.87 2.88 2.88 0.02 2.87 0.95Cations 8.01 8.01 8.01 8.02 8.01 8.01 8.00 8.01 8.00 8.01 8.01 8.01 8.02 8.01 8.02 8.04 8.01 8.01 8.01 8.01 0.01 8.00

Calculated Chemistry:Microprobe Calibration Data

Instrument: Cameca SX50 Xtal El Line Pk(s) Bkg(s) Bkg(+) Bkg(-)Sample Voltage: 15 kV TAP Na Ka 20 10 600 -600Acceleration Current: 20 nA TAP Si Ka 20 10 600 -600Beam Size: Spot TAP Mg Ka 20 10 350 -600Date of Analysis: 12/22/05 TAP Al Ka 20 10 600 -600

PET Ca Ka 20 10 600 -600PET Mn Ka 20 10 600 -600

ACN: Average Number of Cations LIF Fe Ka 20 10 500 -500LIF Ti Ka 20 10 500 -500

StDev: Standard Deviation



Ideal Chemistry: Ca3Fe2(Si O4)3(Ca0.95Mn0.02Fe

2+0.03)3(Fe

3+0.69Al0.30Ti0.01)2(SiO4)3

StandardsAlbite-CrDiopsideDiopsideAnorthite-SDiopsideRhodonite-791Fayalite

NCN: Normalized Cation Numbers =ACN*8/8.01 Rutile1

CNISF=Cation Numbers in structural formulae*=cations normalized for each structural site

R050377 andradite50377#1 #2 #4 #5 #7 #19 Averag StDev

SiO2 32.37 32.15 32.09 32.36 32.29 32.37 32.27 0.12TiO2 5.57 5.57 5.71 5.56 5.68 5.55 5.61 0.07ZrO2 1.86 2.07 2.12 1.79 1.89 2.07 1.97 0.14Al2O3 2.39 2.46 2.44 2.44 2.52 2.44 2.45 0.04Fe2O3 22.86 22.93 22.76 22.89 22.82 22.81 22.85 0.06CaO 33.13 33.02 33.01 33.01 33.03 32.81 33.00 0.10MgO 1.01 1.07 1.02 1.01 1.05 1.00 1.03 0.03Totals 99.20 99.27 99.15 99.07 99.28 99.06 99.17 0.10

Cation Numbe Normal 12.00 O Cation ACN StDev charge (+)Si 2.74 2.72 2.72 2.74 2.73 2.74 2.73 0.01 2.73 4 10.92IVAl 0.24 0.25 0.24 0.24 0.25 0.24 0.24 0.00 0.24 3 0.72IVTi 0.03 0.04 0.04 0.02 0.02 0.02 0.03 0.01 0.03 4 0.12Ca 3.00 2.99 2.99 2.99 2.99 2.97 2.99 0.01 3.00 2 6.00Fe3 1.45 1.46 1.45 1.46 1.45 1.45 1.45 0.00 1.48 3 4.44Ti 0.35 0.35 0.36 0.35 0.36 0.35 0.36 0.00 0.31 4 1.24Mg 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.00 0.14 2 0.28Zr 0.08 0.09 0.09 0.07 0.08 0.09 0.08 0.01 0.07 4 0.28Totals 8.01 8.03 8.02 8.00 8.01 7.99 8.01 0.01 8.00 24.00

ideal Ca3Fe2Si3O12measured Ca3.00(Fe

3+1.48Ti0.31Mg0.14Zr0.07)Σ=2(Si2.73Al0.24Ti0.03)Σ=3O12

Xtal El Line Pk(s) Bkg(s) Bkg(+) Bkg(-) StandardsTAP Si Ka 20 10 600 -600 pyrope2TAP Mg Ka 20 10 600 -600 pyrope2TAP Al Ka 20 10 600 -600 pyrope2PET Ca Ka 20 10 600 -600 diopsidePET Cr Ka 20 10 600 -600 chrom-sPET Zr La 20 10 600 -600 ZrO2LIF Ti Ka 20 10 500 -500 rutile1LIF Fe Ka 20 10 500 -500 fayalite


Rruff ID: R060326 Mineral: AndraditeLocality: Ultevis, Sweden

Weight Percents WDS scan: Si Al Fe Mn Ca TiAnalysis #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 #13 #14 #15 Average Standar DevMgO 0.08 0.06 0.05 0.05 0.05 0.05 0.02 0.06 0.09 0.06 0.04 0.05 0.06 0.07 0.03 0.05 0.02Al2O3 1.78 2.09 2.18 2.36 1.92 1.91 2.06 2.28 2.02 2.03 2.33 2.16 2.29 2.21 2.22 2.12 0.16SiO2 34.60 34.74 34.73 34.64 34.66 34.64 34.68 34.74 35.00 34.80 34.80 34.77 35.10 34.93 34.88 34.78 0.14CaO 32.74 32.64 32.89 33.01 32.71 32.78 32.91 32.66 32.79 32.80 32.76 33.09 33.00 32.98 32.84 32.84 0.13TiO2 0.33 0.35 0.33 0.35 0.34 0.27 0.33 0.33 0.37 0.30 0.34 0.30 0.32 0.31 0.35 0.33 0.02MnO 1.33 1.45 1.50 1.57 1.25 1.28 1.29 1.31 1.25 1.38 1.42 1.29 1.35 1.31 1.48 1.36 0.09Fe2O3 27.30 27.03 26.78 26.84 27.51 27.66 27.02 27.64 27.42 27.60 26.83 27.06 26.99 26.59 26.72 27.13 0.35Totals 98.17 98.39 98.46 98.84 98.47 98.60 98.34 99.03 98.96 98.99 98.54 98.74 99.12 98.42 98.55 98.64 0.28

Cation Numbers on the Basis of 12 Oxygens ACN stdev CNISF* charge (+)Si 2.97 2.97 2.96 2.95 2.96 2.96 2.96 2.95 2.97 2.96 2.96 2.96 2.97 2.98 2.97 2.96 0.01 3.00 4.00 12.00Fe3 1.76 1.74 1.72 1.72 1.77 1.78 1.74 1.77 1.75 1.77 1.72 1.73 1.72 1.71 1.71 1.74 0.02 1.75 3.00 5.25Al 0.18 0.21 0.22 0.24 0.19 0.19 0.21 0.23 0.20 0.20 0.23 0.22 0.23 0.22 0.22 0.21 0.02 0.21 3.00 0.63Ti 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.00 0.04 4.00 0.16Ca 3.01 2.99 3.01 3.01 2.99 3.00 3.01 2.97 2.98 2.99 2.99 3.02 2.99 3.01 3.00 3.00 0.01 2.98 2.00 5.96Mn 0.10 0.11 0.11 0.11 0.09 0.09 0.09 0.09 0.09 0.10 0.10 0.09 0.10 0.10 0.11 0.10 0.01 0.02 2.00 0.04Totals 7.94 7.92 7.93 7.93 7.94 7.94 7.94 7.93 7.93 7.93 7.93 7.94 7.93 7.94 7.93 7.93 0.01 24.00

Ca3Fe3+

2(SiO4)3Calculated Chemistry: (Ca2.98Mn0.02)Σ=3(Fe

3+1.75Al0.21Ti0.04)Σ=2(Si1.00O4)3

totals are low: possible (OH) presentMicroprobe Calibration Data

Xtal El Line Pk(s Bkg(s) Bkg(+) Bkg(-) StandardsInstrument: Cameca SX50 TAP Na Ka 20 10 600 -600 albite-CrSample Voltage: 15 kV TAP Al Ka 20 10 600 -600 anor-hkAcceleration Current: 20 nA TAP Si Ka 20 10 600 -600 diopsideBeam Size: Spot TAP Mg Ka 20 10 600 -600 diopside

PET K Ka 20 10 600 -600 kspar-OR1PET Ca Ka 20 10 500 -500 diopside

ACN: Average Number of Cations PET Ti Ka 20 10 600 -600 rutile1NCN: Normalized Cation Numbers =ACN*8/8.010 LIF Mn Ka 20 10 500 -500 rhod-791StDev: Standard Deviation LIF Fe Ka 20 10 500 -500 fayalite

Ideal Chemistry:

R060358 andradite60358Analysis #5 #8 #9 #10 #11 #12 #13 #14 #15Ox Wt Percent Averag StandarDevMgO 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Al2O3 0.00 0.00 0.00 0.00 0.04 0.04 0.00 0.00 0.00 0.01 0.02SiO2 35.49 35.50 35.40 35.33 35.50 35.43 35.53 35.36 35.65 35.47 0.09CaO 33.19 33.16 33.41 33.26 33.21 33.26 33.18 33.41 33.15 33.25 0.09TiO2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Cr2O3 2.43 1.42 1.39 1.71 1.73 1.57 1.54 1.40 1.39 1.62 0.31MnO 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Fe2O3 28.17 29.27 29.32 29.29 28.97 28.87 29.16 29.26 29.70 29.11 0.40Totals 99.28 99.35 99.53 99.59 99.45 99.16 99.42 99.43 99.88 99.45 0.19

Cation Numbe Normalto 12.00 O ACN StDev NCN CNISF*Si 3.01 3.01 3.00 3.00 3.01 3.02 3.01 3.00 3.01 3.01 0.01 3.00 1.00Fe3+ 1.80 1.87 1.87 1.87 1.85 1.85 1.86 1.87 1.89 1.86 0.02 1.89 0.94Cr 0.16 0.10 0.09 0.12 0.12 0.11 0.10 0.09 0.09 0.11 0.02 0.11 0.06Ca 3.02 3.02 3.04 3.02 3.02 3.03 3.01 3.04 3.00 3.02 0.01 3.00 1.00Totals 8.00 7.99 8.00 8.01 8.00 8.01 7.99 8.01 7.99 8.00 0.01 8.00

theoretical Ca3Fe3+

2(SiO4)3measured

Xtal El Line Pk(s) Bkg(s) Bkg(+) Bkg(-) StandardsTAP Al Ka 20 10 600 -600 anor-hkTAP Si Ka 20 10 600 -600 pyrope-sTAP Mg Ka 20 10 600 -600 pyrope-sPET Ca Ka 20 10 600 -600 diopsidePET Cr Ka 20 10 600 -600 chrom-sLIF Ti Ka 20 10 0 -500 rutile1LIF Mn Ka 20 10 500 -500 rhod-791LIF Fe Ka 20 10 500 -500 fayalite

Ca3.00(Fe3+

1.89Cr0.11)Σ=2(Si1.00O4)3


Rruff ID: R060423 Mineral: AndraditeLocality: Mali

Weight PercentsAnalysis #16 #18 #19 #21 #22 #23 #24 #25 #26 #27 #28 #29 #30 Average StDev

MgO 0.30 0.29 0.28 0.33 0.30 0.28 0.30 0.32 0.32 0.33 0.32 0.33 0.30 0.31 0.02Al2O3 9.77 9.69 9.62 9.57 9.62 9.62 9.66 9.61 9.79 9.63 9.69 9.57 9.67 9.65 0.07SiO2 36.30 36.76 36.69 36.52 37.06 36.78 36.73 36.75 36.77 36.54 36.98 36.60 36.46 36.69 0.21CaO 34.13 34.07 34.03 33.94 33.99 34.02 34.00 33.95 33.89 33.95 34.03 34.03 34.18 34.02 0.08TiO2 2.11 1.70 1.73 1.97 1.89 1.93 1.73 1.93 2.12 1.74 1.95 2.04 1.92 1.90 0.14MnO 0.55 0.46 0.47 0.49 0.43 0.56 0.50 0.45 0.44 0.47 0.57 0.49 0.52 0.49 0.05Fe2O3 16.63 16.54 17.06 16.88 16.90 16.81 16.47 16.81 16.54 16.89 16.66 16.75 16.83 16.75 0.17Totals 99.81 99.52 99.90 99.70 100.18 100.01 99.39 99.82 99.88 99.54 100.20 99.81 99.88 99.82 0.24

Cation Numbers on the Basis of 12 Oxygens ACN StDev CNISF*Si 2.92 2.96 2.94 2.94 2.96 2.95 2.96 2.95 2.94 2.94 2.95 2.94 2.93 2.94 0.01 0.98 4 11.76IVFe3+ 0.08 0.04 0.06 0.06 0.04 0.05 0.04 0.05 0.06 0.06 0.05 0.06 0.07 0.06 0.01 0.02 3 0.18VIFe3+ 0.92 0.96 0.97 0.96 0.97 0.96 0.96 0.96 0.94 0.97 0.95 0.95 0.95 0.96 0.01 0.99 3 2.97Al 0.93 0.92 0.91 0.91 0.91 0.91 0.92 0.91 0.92 0.91 0.91 0.91 0.92 0.91 0.01 0.95 3 2.85Ti 0.13 0.10 0.11 0.12 0.11 0.12 0.11 0.12 0.13 0.11 0.12 0.12 0.12 0.12 0.01 0.06 4 0.24Ca 2.94 2.94 2.93 2.92 2.91 2.92 2.93 2.92 2.91 2.93 2.91 2.93 2.94 2.92 0.01 2.93 2 5.86Mg 0.04 0.04 0.03 0.04 0.04 0.03 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.00 0.04 2 0.08Mn 0.04 0.03 0.03 0.03 0.03 0.04 0.03 0.03 0.03 0.03 0.04 0.03 0.04 0.03 0.00 0.03 2 0.06Totals 7.99 7.98 7.98 7.98 7.97 7.98 7.98 7.98 7.97 7.98 7.97 7.98 7.99 7.98 0.01 24.00

Ca3Fe3+

2(SiO4)3Calculated Chemistry: (Ca2.93Mg0.04Mn0.03)Σ=3(Fe

3+0.99Al0.95Ti0.06)Σ=2(Si0.98Fe

3+0.02O4)3

Instrument: Cameca SX50 Xtal El Lin Pk(s) Bkg(s) Bkg(+) Bkg(-) StandardsSample Voltage: 15 kV TAP Al Ka 20 10 600 -600 anor-hkAcceleration Current: 20 nA TAP Si Ka 20 10 600 -600 pyrope-sBeam Size: Spot TAP Mg Ka 20 10 600 -600 pyrope-s

PET Ca Ka 20 10 600 -600 diopsidePET Cr Ka 20 10 600 -600 chrom-s

ACN: Average Number of Cations LIF Ti Ka 20 10 0 -500 rutile1NCN: Normalized Cation Numbers =ACN*8/8.010 LIF Mn Ka 20 10 500 -500 rhod-791StDev: Standard Deviation LIF Fe Ka 20 10 500 -500 fayalite

Ideal Chemistry:

Electron Microprobe DataRruff ID: R040065 Mineral: GrossularLocality: Feng Tien mine, TaiwanWeight PercentsAnalysis 101 102 103 104 105 107 108 109 110 117 Average St.DevSiO2 39.38 39.82 39.62 39.70 39.44 39.27 39.48 39.50 39.21 40.01 39.54 0.25TiO2 0.35 0.25 0.30 0.24 0.39 0.34 0.38 0.35 0.47 0.19 0.32 0.08Al2O3 22.34 22.31 22.50 22.38 22.75 22.64 22.59 22.37 22.27 22.60 22.47 0.16FeO 1.47 1.49 1.41 1.45 1.59 1.51 1.46 1.43 1.50 1.41 1.47 0.05MnO 0.74 0.76 0.69 0.72 0.66 0.77 0.75 0.72 0.70 0.69 0.72 0.03CaO 36.24 36.42 36.38 36.21 35.94 36.13 36.23 35.93 36.44 36.15 36.21 0.18Total 100.51 101.04 100.90 100.70 100.78 100.66 100.89 100.29 100.59 101.06 100.74 0.24

Average St.Dev formula (+) chargesSi 2.96 2.98 2.97 2.98 2.96 2.95 2.96 2.97 2.95 2.99 2.97 0.01 2.98 4 11.92IVAl 0.04 0.02 0.03 0.02 0.04 0.05 0.04 0.03 0.05 0.02 0.03 0.01 0.02 3 0.06Al 1.94 1.95 1.95 1.96 1.96 1.95 1.95 1.96 1.93 1.97 1.95 0.01 1.95 3 5.85Ti 0.02 0.01 0.02 0.01 0.02 0.02 0.02 0.02 0.03 0.01 0.02 0.01 0.02 4 0.08Fe3+ 0.03 0.03 0.04 0.04 0.07 0.04 0.05 0.06 0.02 0.07 0.04 0.02 0.03 3 0.09Ca 2.92 2.92 2.92 2.91 2.89 2.91 2.91 2.90 2.94 2.89 2.91 0.02 2.90 2 5.80Fe2+ 0.06 0.06 0.05 0.05 0.03 0.05 0.04 0.03 0.08 0.02 0.05 0.02 0.05 2 0.10Mn 0.05 0.05 0.04 0.05 0.04 0.05 0.05 0.05 0.04 0.04 0.05 0.00 0.05 2 0.10Cations 8.02 8.02 8.02 8.01 8.01 8.03 8.02 8.01 8.03 8.00 8.02 0.01 8.00 24.00

Al tot 1.98 1.97 1.98 1.98 2.01 2.00 1.99 1.98 1.97 1.99 1.99 0.01 1.98

Calculated Chemistry: (Ca 2.90Fe2+

0.05Mn0.05)Σ=3(Al 1.95Fe3+

0.03Ti0.02)Σ=2((Si2.98Al0.02)Σ=1O4)3Microprobe Calibration Data

Instrument: Cameca SX50 Xtal El Line Pk(s) Bkg(s) Bkg(+) Bkg(-) StandardsSample Voltage: 15 kV TAP Na Ka 20 10 600 -600 Albite-CrAcceleration Current: 20 nA TAP Si Ka 20 10 600 -600 DiopsideBeam Size: Spot TAP Mg Ka 20 10 350 -600 DiopsideDate of Analysis: 11/24/04 TAP Al Ka 20 10 600 -600 Anorthite-S

PET K Ka 20 10 600 -600 K-spar-OR1PET Ca Ka 20 10 600 -600 DiopsidePET Mn Ka 20 10 600 -600 Rhodonite-791LIF Fe Ka 20 10 500 -500 FayaliteLIF Cr Ka 20 10 500 -500 Chromite-SLIF Ti Ka 20 10 500 -500 Rutile1


Ideal Chemistry: Ca3Al2(Si O4)3

Rruff ID: R040066 Mineral: GrossularLocality: Redding, Connecticut, USAWeight PercentsAnalysis 161 162 163 164 165 166 168 169 170 171 172 173 174 175 176 177 178 Average StDevSiO2 39.03 39.21 39.39 39.09 39.01 39.25 39.39 39.29 39.24 39.08 39.94 39.62 39.45 39.62 39.20 39.07 39.14 39.30 0.25Al2O3 20.55 20.51 20.83 20.80 20.96 20.91 20.88 21.02 21.09 20.34 21.16 20.93 20.86 20.87 20.98 20.90 20.90 20.85 0.21FeO 3.76 3.79 3.96 3.98 3.80 3.77 3.93 3.86 4.01 3.99 3.74 3.89 3.88 3.80 3.89 3.74 3.85 3.86 0.09MnO 0.29 0.31 0.27 0.28 0.26 0.28 0.29 0.29 0.25 0.27 0.27 0.27 0.27 0.35 0.26 0.25 0.27 0.28 0.02CaO 36.10 35

1 determining chemical composition of the silicate garnets using raman spectroscopy … · 2018. 1....

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