1. Objectives Vocabulary
Identifying Minerals
Objectives
Classify minerals according to their physical and chemical properties.
Identify different types of minerals.
Vocabulary
luster
streak
hardness
cleavage
fracture

2. Mineral Identification
Identifying Minerals
Mineral Identification
Geologists rely on several relatively simple tests to identify minerals.
Physical properties
Chemical properties.
It is usually best to use a combination of tests.

3. Mineral Identification
Identifying Minerals
Mineral Identification
Color
Noticeable characteristic.
Can be caused by the presence of trace elements.
Least reliable clue to a mineral’s identity.

4. Mineral Identification
Identifying Minerals
Mineral Identification
Luster
Luster is the way that a mineral reflects light from its surface.
metallic or nonmetallic.

5. Mineral Identification
Identifying Minerals
Mineral Identification
Texture
Texture describes how a mineral feels to the touch.
smooth, rough, ragged, greasy, soapy, or glassy.

6. Mineral Identification
Identifying Minerals
Mineral Identification
Streak
Streak is the color of a mineral when it is broken up and powdered.
Sometimes, a mineral’s streak does not match the mineral’s external color.
A mineral’s streak rarely changes.

7. Mineral Identification
Identifying Minerals
Mineral Identification
Hardness
Hardness is one of the most useful and reliable tests for identifying minerals.
Hardness is a measure of how easily a mineral can be scratched.
Any mineral with a greater hardness than another mineral will scratch that softer mineral.

8. Mineral Identification
Identifying Minerals
Mineral Identification
Hardness

9. Mineral Identification
Identifying Minerals
Mineral Identification
Cleavage and Fracture
Minerals break along planes where atomic bonding is weak.
Cleavage is the ability of a mineral to split relatively easily and evenly along one or more flat planes.
Fracture is the ability of minerals to break with arclike, rough, or jagged edges.

10. Mineral Identification
Identifying Minerals
Mineral Identification
Cleavage and Fracture

11. Two more specialty tests…
Magnet
Magnetite is magnetic
Hydrochloric acid (HCl)
Calcite = fizzing
Quartz = no fizzing

12. Identifying Minerals
Section Assessment
1. Match the following terms with their definitions.
___ streak
___ hardness
___ cleavage
___ fracture C D B A
A. the ability to break with arc-like, rough, or jagged edges
B. the ability to split relatively easily along one or more flat planes
C. the color of a mineral when it is broken up and powdered
D. a measure of how easily a mineral can be scratched

13. End of Section 2

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