1. Minerals

2. Mineral
Definition

3. 1. A mineral is naturally occurring…
2. A mineral is inorganic (was never alive)…
3. A mineral is solid…

4. 4. A mineral is crystalline (made of crystals)
5. A mineral has a definite chemical composition (composition doesn’t change)
6. A mineral has definite physical properties

5. There are over 3000 minerals!
Common Minerals
There are over 3000 minerals!
Only about 30 are commonly found in the Earth’s crust

6. The Rock Forming Minerals
The 30 (or so) common minerals that form most rocks on the Earth’s crust

7. Natural or synthetic (man made) Living or non-living
Review: A mineral is…(choose one answer)
Natural or synthetic (man made)
Living or non-living
Solid, liquid or gas
Definite or variable properties
There are about 3000 or 30 minerals that form most rocks
Is ice a mineral?

8. Based on SEVERAL PROPERTIES
Identifying Minerals
Based on SEVERAL PROPERTIES
Each property tells only part of the mineral’s identity
All properties caused by the INTERNAL ARRANGEMENT of ATOMS in the MINERAL

9. Luster is the way a mineral shines or reflects light
Two Types:
ESRT
Metallic
Non-Metallic

10. 2 minerals with metallic luster 2 minerals with non-metallic luster
ESRT
Review: ESRT p 16
2 minerals with metallic luster
2 minerals with non-metallic luster
A mineral that can have either metallic or non-metallic luster
What causes a mineral to have either type of luster?

11. Hardness: resistance to being scratched
Based on MOH’S Scale of hardness
Hardness of 1: softest (least resistant)
Hardness of 10: hardest (most resistant)

12. Fingernail: hardness of 2.5
MOH’s Scale
Fingernail: hardness of 2.5
If mineral scratches fingernail, it has a greater hardness (>2.5)
Penny: hardness of 3.0
A mineral that scratches a penny has a hardness of > 3.0

13. If mineral scratches a nail, it has a greater hardness (>5.5)
MOH’s Scale
Nail: Hardness of 5.5
If mineral scratches a nail, it has a greater hardness (>5.5)
Glass: hardness of 6.5
A mineral that scratches glass has a hardness of > 6.5

14. What causes a mineral’s hardness?
ESRT
Review: ESRT p 16
2 minerals that will not scratch your fingernail
2 minerals with will scratch a penny but NOT a nail (hardness between 3 and 5)
Two minerals that will scratch glass
What causes a mineral’s hardness?

15. Cleavage: if a mineral breaks evenly When a mineral has flat surfaces…
Cleavage and Fracture
Cleavage: if a mineral breaks evenly
When a mineral has flat surfaces…
Or regular shapes

16. Fracture: if a mineral breaks unevenly
Cleavage and Fracture
Fracture: if a mineral breaks unevenly
When a mineral has an irregular shape

17. 2 minerals with cleavage 2 minerals with fracture
ESRT
Review: ESRT p 16
2 minerals with cleavage
2 minerals with fracture
What causes a mineral to have either cleavage of fracture?

18. But the NOT VERY useful! WHY? Many minerals have similar colors
Caused by the type of atoms in the mineral
Easy to observe!
But the NOT VERY useful! WHY?
Many minerals have similar colors

19. Some minerals have many colors
NOT VERY useful! WHY?
Some minerals have many colors

20. 2 minerals that can be green 2 minerals that can be white
ESRT
Review: ESRT p 16
2 minerals that can be green
2 minerals that can be white
What causes a mineral’s color?

21. Distinguishing Characteristics
Unique properties that identify minerals
STREAK: The color of a mineral in powdered form
Not always the same as color!
This mineral
has a brown streak

22. Distinguishing Characteristics
Unique properties that identify minerals
Can also include how a mineral looks, feels or tastes!
This mineral
Reacts in acid
This mineral is
magnetic

23. 2 minerals that bubble in acid 2 minerals that have greasy feel
ESRT
Review: ESRT p 16
2 minerals that bubble in acid
2 minerals that have greasy feel
What causes a mineral’s distinguishing characteristics?

24. Chemical Composition The chemical elements a mineral is made from
Metallic Minerals – contain metal elements
Pyrite contains IRON

25. Most Minerals (over 60%) contain Silicon and Oxygen
Chemical Composition
Most Minerals (over 60%) contain Silicon and Oxygen
These minerals are called SILICATES
Silicates contains Si and O arranged in
pyramid shape called silica tetrahedron
Chemical formula SiO4

26. 2 minerals that are silicates
ESRT
Review: ESRT p 16
2 minerals that are silicates
2 non-metallic minerals are not silicates
Two metallic minerals
What creates a mineral’s chemical composition?

27. Review: Use notes and ESRT
What type of luster in mineral A?
What type of luster in mineral B?
Which mineral has cleavage?
Which mineral has fracture?
A B

28. Review: Use notes and ESRT
What is the hardness of a mineral that will scratch a nail but not scratch glass?
What is the hardness of a mineral that will not scratch penny?
Which mineral has a red-brown streak?
One non-metallic mineral containing silica tetrahedra.
The number of rock forming minerals
A very hard, red mineral found in NYS
ESRT

29. crystal shapes
Crystal shape can be a useful property to identify minerals if the minerals have had the time and space to form crystals. Most mineral grains that are found in rocks, lack the room to grow.

30. Pure gold can have a specific gravity as high as 19.3!
Specific gravity tells you how many times as dense as water the mineral is.
Pure gold can have a specific gravity as high as 19.3!

31. acid test
Calcite is calcium carbonate, CaCO3. If a drop of weak hydrochloric acid is placed on calcite, the acid bubbles as carbon dioxide is released.

32. Other Special Properties Magnetic Malleable Radioactive Flourescence
Taste

33. Can you think of a mineral that might be shaped or hammered?
Malleable
or Ductile
Minerals that can be hammered thin or shaped are said to show these properties.
Can you think of a mineral that might be shaped or hammered?

34. Gold would be a perfect example!

35. p9
p10
p14
p17
p20
p23
p26
p27
p28

37. Magnetic
Some minerals that contain Iron, are magnetic and can be picked up by a magnet.

38. This is the state of glowing while under a ultraviolet light.
Fluorescence
This is the state of glowing while under a ultraviolet light.
Some minerals even glow once the light is turned off!

39. Some minerals, such as this uraninite, are radioactive.
They give off subatomic particles that will activate a Geiger counter.

40. Halite (rock salt) can be identified by its taste.
This practice is not recommended!