1. Minerals

2. What is a Mineral?
Naturally-formed solid substance with a crystal structure
Pyromorphite

3. What do all minerals have in common?
Are formed by natural processes.
Are NOT alive and NEVER were alive
Have a definite volume and shape
Are elements or compounds with a unique chemical makeup
Are made up of particles that are arranged in a pattern that is repeated over and over (called a CRYSTAL)

4. What do all minerals have in common?
They must occur naturally within the earth.
Cement, bricks, steel, and glass are not minerals because they are man made.

5. What do all minerals have in common?
Minerals must be inorganic. This means that they cannot arise from materials that were once part of a living thing.
Coal is not a mineral because it comes from the remains of plants and animals

6. What do all minerals have in common?
Minerals have a definite volume and shape.
The particles that make up the sample do not move apart.

7. What do all minerals have in common?
Minerals have definite chemical compositions.
A mineral always contains certain elements in definite proportions.
Most minerals are compounds.
Compounds are two or more elements combined.
Some minerals are just elements Copper, Gold, and Silver.

8. What do all minerals have in common?
Minerals have crystal structures. These are particles in minerals that line up in a pattern that repeats over and over again.
Sometimes a crystal structure is obvious and sometimes its only visible under a microscope.

9. Watch “Crystals” by Brainpop…
.What element are diamonds made from?
. What do all crystals have in common?

10. Groups of Minerals
Minerals are grouped by the elements they are made of.
Beryl (Emerald)
Calcite
Amethyst

11. Contain oxygen & silica The most abundant group of minerals
Mineral Group
Characteristics
Examples
Silicates
Contain oxygen & silica
The most abundant group of minerals
Quartz, mica
MICA
Quartz

12. Make up only 5% of the Earth’s crust
Mineral Group
Characteristics
Examples
Non-Silicates
Make up only 5% of the Earth’s crust
Include some of the most important minerals
iron, copper, gold, silver, diamonds, rubies
Silver
Copper
Diamond
Gold
Iron
Ruby

13. Carbon & oxygen and a positive ion, such as calcium Calcite (CaCO3)
Mineral Group
Characteristics
Examples
Carbonates
Carbon & oxygen and a positive ion, such as calcium
Calcite (CaCO3)
Calcite with Duftite inclusions

14. Mineral Group
Characteristics
Examples
Oxides
Metallic ion and oxygen
Hematite (Fe2)O3

15. Mineral Group
Characteristics
Examples
Sulfides
Sulfur and a metallic ion
Galena (PbS)

16. Metallic ion, Sulfur & oxygen Barite (BaSO4)
Mineral Group
Characteristics
Examples
Sulfates
Metallic ion, Sulfur & oxygen
Barite (BaSO4)
Barite BaSo4
Barite on Calcite BaSo4 / CaCO3

17. Mineral Group
Characteristics
Examples
Native Elements
Single elements
Gold (Au), Diamond (C), Silver (Ag)

18. How do minerals form?
1) Cooling of magma (hot, liquid rock and minerals inside the earth (from the mantle))
Fast Cooling = No Crystals (mineraloids)
Medium Cooling = small crystals
Slow Cooling = large crystals

19. How do minerals form?
2) Elements dissolved in liquids (usually water)

20. Physical Properties of Minerals
Mineral appearance
Hardness
Luster
Specific gravity
Streak
Cleavage and fracture

21. Physical Properties of Minerals (can be used to identify the mineral)
Color
Can be misleading
Can vary with the type of impurities

22. Physical Properties of Minerals (can be used to identify the mineral)
Hardness
How easily a mineral scratches materials
Mohs Hardness Scale
Scale from 1 (softest) to 10 (hardest)
Test by seeing if the mineral can scratch different objects (like human fingernail, copper, penny, glass, steel file)

23. Properties of Minerals
Mohs Hardness Scale
Mineral
Talc
Gypsum
Calcite
Fluorite
Apatite
Feldspar
Quartz
Topaz
Corundum
Diamond
Rating
Testing Method
1 Softest known mineral. It flakes easily when scratched by a fingernail.
2 A fingernail can easily scratch it.
3 A fingernail cannot scratch it, but a copper penny can.
4 A steel knife can easily scratch it.
5 A steel knife can scratch it.
6 Cannot be scratched by a steel knife, but it can scratch window glass.
7 Can scratch steel and hard glass easily.
8 Can scratch quartz.
9 Can scratch topaz.
10 Hardest known mineral. Diamond can scratch all other substances.

24. Find out more… “Electronic” Hardness Test

25. Physical Properties of Minerals (can be used to identify the mineral)
Luster
Surface reflection
metallic = shiny like metal
non-metallic = dull, non-shiny surface
Pyrite has a metallic luster
Calcite has a non-metallic luster

26. Specific Gravity or Density
The specific gravity of a mineral is the ratio of its mass compared with the mass of an equal volume of water.
Gold has specific gravity of 19
It means gold is 19 times heavier than water.
19 times heavier

27. Density

28. Physical Properties of Minerals (can be used to identify the mineral)
Streak
The color of the powdered form of the mineral
The color of the streak can be different than the mineral
Minerals must be softer than the streak plate

29. Streak…can help identify quartz
BUT...

30. Physical Properties of Minerals (can be used to identify the mineral)
Cleavage & Fracture
The way the mineral breaks
Cleavage—minerals break along smooth, flat surfaces and every fragment has the same general shape
Fracture—minerals that break at random with rough or jagged edges

31. Cleavage Cleavage is the way that mineral breaks.
Minerals that break along smooth, flat surfaces have cleavage.
Mica has cleavage

32. and Fracture!...
Mineral that breaks uneven, rough, or jagged surfaces have fracture.
Quartz has fracture
quartz

33. Identify the minerals below for cleavage and fracture

34. Physical Properties of Minerals (can be used to identify the mineral)
Other Properties
Specific gravity (*excellent clue to mineral’s identity)
Attraction to magnets
Bending of light
Reaction with hydrochloric acid
Smell & taste

35. An illustration appearance:luster,color and streak

36. An illustration cleavage and fracture

37. Watch Classifying Minerals Clip

38. Watch Brainpop—“Mineral Identification”
. If a mineral can scratch your fingernail, the mineral is _______________ than your fingernail.
2. What is luster?