Transcript What Is A Mineral?

What Is A Mineral?
Characteristics and properties used to
identify minerals.
What are characteristics of minerals?
 Solid
 Formed in nature
 Non-living
 Crystalline structure

Particles line up in a repeating pattern
What are the Six Physical
Properties of Minerals?
Used to identify all minerals
1. Color
 The surface color of the mineral
 Minerals come in a variety of colors
Examples of Mineral Colors
2. Luster
 The way a surface reflects light.
(glassy, metallic, waxy, shiny, etc.)
Examples of Luster
Metallic
Looks like metal
Pearly
Looks like a pearl
Vitreous/Glassy
Looks like glass
Dull
Non-reflective
Resinous
Look of dried glue
Earthy
Looks like dried mud
3. Streak
 The color of the mineral in powdered form.
 Streak color and mineral color are often
different.
 Examples:
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Hematite – brick red
Galena – steel gray
Pyrite – brassy yellow or black
Olivine – white
Feldspar – white
Talc – white
Gypsum – colorless
Examples of Streak
4. Cleavage & Fracture
 Cleavage = tendency of minerals to break
along a flat surface.
 Fracture = tendency of minerals to break
unevenly along a curved or irregular surface
Examples of Cleavage
Cube or cubic
Octahedron
or Octahedral
Pinacoid –
2 parallel faces
Pyramid
Dome
Prism
Examples of Fracture
Conchoidal
Jagged
Subconchoidal
Splintery
Uneven
Earthy
5. Hardness
 A mineral’s resistance to being scratched.
 Any mineral with a higher hardness rating can
scratch a mineral with a lower hardness
rating.
 Diamond is the hardest natural substance
known to humans.
Moh’s Hardness Scale
1.
2.
Talc
Gypsum
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--fingernail at 2.5
3. Calcite
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--copper (old penny) at 3.5
4. Fluorite
5. Apatite
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--window glass or typical knife blade at under 5.5
6. Orthoclase
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--streak plate or good steel file at over 6.5
7. Quartz
8. Topaz
9. Corundum
10. Diamond
6. Density
 How much matter there is in a given amount
of space.
 Galena – specific gravity = 7.4 to 7.6
What are some Special Properties?
Fluorescence
Magnetism
Taste
Light refraction
Odor
What are some uses of minerals?
 Coins
 Jewelry
 Electrical wires
 Batteries
 Paint
 Steel
 Building materials
 etc.
Rocks are made out of
minerals, but minerals are
not made of rocks.