Transcript Minerals

Minerals
Chapter 3
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Minerals – naturally occurring, inorganic solid
with a definite structure and composition
Over 4000 minerals
5 Characteristics of Minerals:
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formed by natural processes – salt, diamonds
Inorganic – no Carbon
Solids
Unique chemical composition
repeated pattern
Crystals – solid with atoms are arranged in
repeating patterns
Minerals formed:
1. from magma – cooling of hot melted rock
2. liquid evaporating - crystals
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Silicates – minerals that contain silicon and oxygen
and usually one or more other elements
Silicon and Oxygen the two most abundant elements
in earths crust
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Mineral Identification
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1. Physical Properties –
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Color
Appearance
Hardness – Mohr hardness scale
Luster – how light is reflected
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Metallic or non metallic
Streak – color of the mineral when it is broken up and
powdered
Cleavage and fracture – how it breaks
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Cleavage – breaks along smooth flat surfaces Mica
Fracture – rough, jagged edge - Quartz
Luster – how light is reflected
Metallic or non metallic
Streak – color of the mineral when
it is broken up and powdered
Hardness
3.2 How Minerals Form
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In crystallization the atoms are arranged
either by:
1. Magma and Lava
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Hot magma cools inside the earth
Lava (magma on the surface) hardens on the
surface
Both form crystals when they cool to a
solid
2. Solution
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Elements and compounds dissolved in water
leave a solution they form crystals
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Minerals form by evaporation
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Salt, halite, gypsum, calcite
Minerals from Hot Water Solutions
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Elements and compounds dissolve
Vein – narrow channel or slap of a mineral
different from the surrounding rock
3.3 Mineral Resources
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Uses of Minerals:
1. Gemstones – hard, colorful, mineral with a
glassy luster
2. Metals – aluminum, iron, copper or silver
3. Misc: Talc for talcum powder
 Calcite for optical instruments like
microscopes
 Quartz for class and electronics
 Gypsum - wallboard and cement
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4. Ore
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– rock that contains a useful
mineral that can be sold for profit