Minerals

1
Minerals
2
Background Information

• Element a substance made up of only one kind of
  atoms
• Example Gold (Au), Aluminum (Al)
• Compound a mixture of two or more elements
• Example Salt (NaCl) Sodium and Chlorine

3
What is a Mineral?

1. Naturally occurring
2. InorganicNot Living
3. Solid
4. Crystal Structure
5. Definite Chemical Composition

4
Minerals can form two ways

• 1. Magma and Lava
• Minerals form as hot magma cools inside the
  crust, or as lava hardens on the surface.
• When these liquids cool to a solid state, they
  form crystals.

5

• Solutions
• Solution is a mixture in which one substance is
  dissolved in another.
• When elements and compounds that are dissolved in
  water leave a solution, crystallization occurs

6

• Some minerals form when solutions evaporate.
• Example Death Valley

7
Identifying a Mineral

• Each mineral has characteristic properties that
  can be used to identify it.

8
Color

• Color of a mineral is an easily observed physical
  property.
• Light or Dark?
• Halite hematite

9
Streak

• The mineral is rubbed against a piece of
  unglazed porcelain tile.
• Sometimes the streak color and the mineral color
  are different.

10
Luster

• Luster is how a mineral reflects light.
• Metallic
• Nonmetallic includes glassy, earthy, waxy and
  pearly.
• Galena Quartz

11
Density

• Each mineral has a characteristic density.
• Density mass/volume

12
Hardness
1 Softest Ex. Talc Fingernail
2 Ex. Gypsum fingernail
3 Ex. Calcite Penny
4 Ex. Flourite Steel knife
5 Ex. Apatite Steel knife can scratch it
6 Ex. Feldspar It can scratch glass
7 Ex. Quartz Steel hard glass
8 Ex. Topaz Can scratch quartz
9 Ex. Corundum Can scratch topaz
10 Hardest Ex. Diamond Will scratch all other substances
13
Cleavage

• A mineral that splits easily along flat surfaces.

14
Fracture

• Fracture is when a mineral breaks in an irregular
  way.

15

• Each mineral grows atom by atom to form a
  particular Crystal Structure
• crystal structure
• Two main types
• Cubic--Halite
• Hexagonal--Quartz