1. Mineral Identification

2. Anticipation Guide #2 1) Rocks cannot be made of organic material
2) Luster is classified as metallic and non-metallic
3) Scientist use tests to identify minerals
4) Minerals that make up rocks can be mined as ores
5) A liquid or gas can be classified as a mineral

3. VA SOL
ES 4 The student will investigate and understand how to identify major rock-forming and ore minerals based on physical and chemical properties. Key concepts include
a. properties including hardness, color and streak, luster, cleavage, fracture, and unique properties; and.

4. Objective
3 Define chemical and physical properties of minerals to include luster, hardness, cleavage, fracture, streak, color, specific gravity, and special traits.

5. Enduring Understanding
Minerals are the building blocks of rocks.

6. Mineral Identification
With more than 3,000 minerals in Earth’s crust how does one go about identifying an unknown mineral?

7. Mineral Identification
Geologists rely on several simple tests that are based on a mineral’s physical and chemical properties. It is usually best to use a combination of tests rather than just one to identify minerals

8. Mineral Properties
Color is one of the most noticeable but least reliable characteristics

9. Mineral Properties Quartz
Sometimes caused by the presence of trace elements or compounds
Quartz

10. Mineral Properties
Streak is the color of the mineral when it is broken up into a powder and is a much more reliable identification method because it rarely changes
Both of these samples are hematite; both have a reddish-brown streak

11. Mineral Properties
Streak is easily determined by rubbing the mineral across an unglazed porcelain plate

12. Mineral Properties
Streak is used to distinguish pyrite from gold

13. Mineral Properties Pyrite Gold
Streak is used to distinguish pyrite from gold
Pyrite
Gold

14. Mineral Properties
Luster is the way a mineral reflects light from its surface and is caused by differences in mineral chemical compositions

15. Mineral Properties
Either metallic or nonmetallic (dull, pearly, waxy, silky)

16. Mineral Properties Texture describes how a mineral feels to the touch
Rough, smooth, ragged, greasy, soapy, glassy

17. Mineral Properties
Hardness is a measure of how easily a mineral can be scratched and is determined by the arrangement of it’s atoms.

18. Mineral Properties
The Mohs hardness scale is used to compare a sample to the hardness of ten known minerals

19. Mineral Properties
Cleavage determines whether a mineral will split easily and evenly along one or more flat planes

20. Mineral Properties Mica has perfect cleavage in one direction
Halite has cubic cleavage (3 planes)

21. Mineral Properties
Fracture means the mineral is tightly bonded and breaks with rough or jagged edges
Quartz has fracture

22. Mineral Properties
Specific Gravity compares the weight of the mineral to an equal volume of water at 4 degrees C

23. Mineral Properties
Special Properties such as light reflection and reactions to acids are also useful tools

24. Mineral Properties
Calcite fizzles when in contact with HCl

25. Mineral Properties
Calcite also can cause double images

26. Mineral Properties
Magnetite will attract iron

27. Mineral Properties
Sulfur produces a rotten egg odor