1. Minerals Are:
* Solid, inorganic materials that form naturally on or beneath the Earth’s surface.

2. Have a definite chemical composition.
Usually solid. High temp. inside the Earth can melt them.

3. Naturally Occurring – not man-made
Naturally Occurring – not man-made. Formed as a result of processes in the natural world.

4. Inorganic – not made from things that were once alive.

5. Have definite crystal structure – repeating patterns of a mineral’s atoms.

6. Definite Chemical Composition –
Each type of mineral has the same proportions of the same elements.

7. How Mineral Form
Most minerals form when molten material (magma) cools and hardens inside Earth or on the surface
Some form when a solution evaporates on Earth’s surface
Ex. Halite NaCl

8. How Minerals are Formed
If magma or lava cool slowly then large crystals will form
Ex. Quartz
If magma or lava cool quickly the small crystals will form
Ex. Feldspar

9. Identify Minerals
Look at the Properties – characteristics that make the mineral different from other minerals.

10. Ways to Identify:
Hardness
Color
Streak
Luster
Cleavage
Density

11. Identifying Minerals
Hardness- use Moh’s hardness scale p 95 of textbook

12. Color
Not good to use.
Several minerals come in different colors.

13. Streak
- color of the mineral’s powder found when the mineral is rubbed on a piece of tile

14. Luster
- how a mineral reflects light: glassy, pearly, metallic, and earthy

15. Cleavage & Fracture
Cleavage: split apart easily along flat surfaces.
Fracture: irregular surface where it breaks

16. Cleavage

17. Fracture

18. Density Density = mass/volume Use a balance to find mass in grams
Use a graduated cylinder to find volume in milliliters

19. Other Properties: Chemical reaction: fizzes with vinegar (Calcite)
Transparent – can see through it
Opaque – pearly, cloudy
Magnetic * High Mass