from the town of bedrock, its a place right out of history
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From The Town Of Bedrock, Its a Place Right Out Of History. A mineral defined. the solid portion of the earth is composed of rocks rocks are composed of minerals All minerals are defined by the following : Naturally occurring: mother nature makes minerals…not us! - PowerPoint PPT PresentationTRANSCRIPT
From The Town Of Bedrock, Its a Place Right Out Of History
A MINERAL DEFINED the solid portion of the earth is composed of rocks rocks are composed of minerals All minerals are defined by the following:
Naturally occurring: mother nature makes minerals…not us! Inorganic: made of things that are not living and never will be
living! Solid: hard and breakable Homogeneous: the same throughout Definite chemical composition: unique combination of elements Crystalline structure: repeating pattern of atoms that creates
crystals
A MINERAL IDENTIFIED There are 6 traits you can
test to help you correctly identify a mineral sample
1. Color2. Hardness
3. Streak4. Cleavage/Fracture
5. Luster6. Unique characteristics
COLOR Color is okay to look at
initially, but you can not base your decision only on that one trait
Why? Trace elements can vary the external color.
If we only looked at color, we would not identify it correctly.
These are both diamonds
CAN YOU SCRATCH IT? When you try to scratch a
mineral, you are testing its hardness
If it can be scratched, then it is softer than the object you used to scratch it
If it cannot be scratched, then it is harder than the object you used to scratch it
Common minerals and their hardness are ranked on Moh’s Hardness Scale, listed from the softest to the hardest
FIELD HARDNESS CHART page 106
WE HAVE A STREAKER!!
The streak of a mineral is the mineral in its powdered form
Minerals will only have a streak if they are softer than the streak plate (which has a hardness of 7)
If the mineral has a metal in its chemical formula, it will usually leave a streak
The streak color will not always be the same color as the mineral…so don’t assume!
I NEED A BREAK!!! Cleavage and
fracture are two terms used to describe how a mineral breaks
Cleavage means it breaks with smooth, flat surfaces
Fracture means the mineral breaks along jagged surfaces
OH, HOW IT SHINES! How a mineral shines
describes its luster If it shines like a metal, it
has metallic luster If it does not shine like a
metal, it has nonmetallic luster1. Dull2. Glassy3. Earthy4. Pearly5. Waxy
UNIQUE CHARACTERISTICS Magnetism
(magnetite) Double refraction,
double image (calcite) Fizzes when acid is
placed on it (calcite) Fluorescence (glows
under a black light) Olfactory (sulfur)
smell Specific gravity: one
of the best tests to help you identify a mineral !