1. Minerals What are minerals?
A naturally occuring, crystalline inorganic substance.
What properties do we use to classify minerals? (7 properties)
Color
Luster
Streak
Crystal shape
Hardness
Cleavage
Density

2. What is a Mineral? 1. Occurs naturally 2. Solid
3. Has a defined chemical composition
4. Atoms arranged in an orderly pattern
5. Was never alive- Inorganic

3. Mineral Identification
Approximately 4,000 known minerals
About 30 are common
These are the rock forming minerals (because they are the most common minerals in rocks!)
Your ESRT helps you identify minerals

4. Formation
From cooling of magma or lava
Evaporites
Precipitates

5. Distribution of elements within the lithosphere

6. Structure of Minerals

7. Types of minerals Native Silicates Silica tetrahedron Non-silicates
Composed of a single element
Silicates
Composed of Silicon and Oxygen
Silica tetrahedron
Non-silicates
Oxides- Contains O+2
Sulfates- Contains Sulfur
Carbonates- Contains Carbon

8. Minerals
Minerals are identified by their physical characteristics. These include:
Streak
Color
Luster
Hardness
Density (specific gravity)
Crystal structure

9. Mineral ID  What is the streak of hematite? (hint:use your ESRT)
The color of the powdered mineral
Test by rubbing sample against unglazed porcelain
 What is the streak of hematite? (hint:use your ESRT)

10. Streak

11. Mineral ID  Why is color not very reliable (ESRT)? Color
least reliable
 Why is color not very reliable (ESRT)?

12. Color “Don’t judge a mineral by its color”

13. Mineral ID Luster The way light reflects from a freshly broken surface
Metallic
Nonmetallic

14. Luster

15. Hardness

16. Hardness

17. Arrangement of Atoms Influences Cleavage:

18. Cleavage Minerals that do not have cleavage tend to fracture
Look for flat or step like surfaces
Minerals that do not have cleavage tend to fracture

19. Be careful: cleavage is not the same as crystal shape!
form when the mineral is allowed to cool and the molecules arrange themselves in a repeating pattern.
Size and appearance of crystals depend on environment of formation
Crystals need room to grow.
Crystal form is the way a mineral GROWS
Cleavage and fracture
Planes along which the mineral tends to break
Cleavage is the way a mineral BREAKS

20. Density Specific Gravity
Ex: Gold has a density of 19 g/cm3 , if we have a 2 gram sample, what would the samples volume be?

21. Mineral ID
Density

22. Other Properties
Bubbles
“fizzzz”

23. Fluorescence

24.  (ESRT) What is the hardness of olivine?
Does calcite exhibit cleavage when broken?
What is one of the uses of biotite?
Which minerals react to acid?