luster hematite may vary in color but the streak will always be reddish brown

Starter:

What is the density of a cube with a side length of 3 cm and a mass of 27 grams?

Volume= length x width x height

Density= Mass/volume

Minerals

Minerals: From the Inside OutMinerals are the building blocks that make up rocks

There are about 3000 known minerals.

Answer These Questions To be a mineral, all of the following questions must be

answered “yes”:

1. Is it nonliving material? A mineral is inorganic.

2. Is it formed in nature? Only naturally made crystals are classified as minerals.

3. Does it have a crystalline structure (repeating inner structure that determines shape)?

4. Is it a solid? No gases or liquids allowed.

Identifying Minerals

Color

• Impurities can change color

• Air and water can also change color of mineral

Identifying Minerals (cont.)Luster

• How the surface of a mineral reflects light.

• Controlled by how atoms are bonded

• Metallic, submetallic, nonmetallic (vitreous, silky, resinous, waxy, pearly, earthy)

Luster

Luster

Identifying Minerals (cont.)Streak

• Color of mineral in powdered form

• Not always the same as color of mineral sample

• More reliable than color of mineral

Hematite may vary in color but the streak will always be reddish brown.

Identifying Minerals (cont.)Cleavage and Fracture

• How mineral breaks, determined by atomic arrangement

Cleavage – tendency to break along flat surfaces (mica, halite) because bonding is weakest in those directions.

Fracture – tendency to break along curved or irregular surfaces (quartz – conchoidal) when bonding is equally strong in all directions.

Identifying Minerals (cont.)Hardness

• Resistance to being scratched

• Mohs hardness scale:

Talc, Gypsum, Calcite, Fluorite, Apatite, Orthoclase, Quartz, Topaz, Corundum, Diamond

Hardness Scratch Test

< 2.5 = Mineral marks paper

2.5 = Fingernail

3 = Copper Penny

5 = Steel knife blade

6 = Plate of glass

6.5 = Steel file

Identifying Minerals (cont.)Density

• How much matter there is in a given amount of space (D = m/v) (g/ cm³)

Study Jams Mineral Slideshow

Click the link below. Watch the slideshow. When you are done with the slideshow you will take the quiz. You will answer the quiz on the computer and on your handout.

http://studyjams.scholastic.com/studyjams/jams/science/rocks-minerals-landforms/minerals.htm

Identifying Minerals Video

Click the link below. Watch the video. When you are done you will write down two things you learned and one thing you still have questions about on your handout.

https://www.youtube.com/watch?v=32NG9aeZ7_c

If you finish early….

http://www.lizzadromuseum.org/game/basic.html

http://www.glencoe.com/sites/common_assets/science/virtual_labs/ES03/ES03.swf