Mineral Formation

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Mineral Formation
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The Earths crust is made up of two things

• Minerals and Rocks

Rocks are combinations of minerals
Minerals are individual crystals of all the same
stuff
You should see lots of different minerals in
every single rock
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What is a mineral?

• Main Concept Minerals are the building blocks of
  rocks!
• There are four main properties of a mineral
• a) It must occur naturally (not fake)
• b) It is made of non-living material (never
  alive)
• c) It has a definite chemical formula (NaClsalt)
• d) It has a crystal structure (OOoo! Precious!)

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Examples
Notice how each is one single type of crystal!

• Amethyst Calcite Garnet
• Galena Gold Pyrite

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Where do minerals come from?

• Mineral crystals can form in two main ways

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Minerals Crystals from Magma Lava
Extrusive Cooling Lava cools Fast (Short Time
Small Crystals)

• Minerals form from hot magma as it cools inside
  the crust, or as lava cools on the surface.
• When these liquids cool to a solid, they form
  crystals (minerals).
• Size of the crystal depends on time it takes to
  freeze into a solid.

Intrusive Cooling Magma cools slowly (Long
Time Large Crystals)
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Minerals Crystal Size
When the hot material cools fast, it has smaller
crystal size. When it cools slowly, it has large
crystals.
Granite
Rhyolite
You can see individual crystals in Granite
cooled slowly
You cant see many individual crystals in
Rhyolite cooled very fast
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Minerals formed by Evaporation

• Some minerals form when solutions/mixtures
  evaporate
• When water evaporates, it leaves behind the stuff
  thats dissolved in it.
• The longer it takes to evaporate, the larger the
  crystal.
• i.e. salt water ocean,
• Halite, Gypsum, Calcite.

All the white stuff salt mineral crystals
that formed when the water of this lake
evaporated. The mineral material was left behind
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These salt crystals formed from salt water
because as the water evaporated, the salt wasnt
dissolved anymore. So the chemical energy in salt
takes over and crystals form.
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How do we identify Minerals?
We use the different physical and chemical
properties of the mineral to identify it from
other different minerals
Luster Describes how light is reflected from a
minerals surface.
Streak Is the color of the minerals powder when
dragged across a surface.
Crystal shape Different minerals make different
crystal shapes
Hardness Hardness is determined by a scratch
test.
Color Every mineral has some natural colorex
Gold, Blue, Clear
Etc There are many other types of properties we
use but these are the big ones
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Special Properties

• Some minerals display strange properties.
• These can include Magnetism, fluorescence, and
  reactivity.

Fizzing!
These minerals glow in the dark. A black light
really brings it out!
The minerals in this rock react with acid
The particles of minerals of this rock act like
magnets