Minerals
What is the difference in picture A
and B? (Other than the obvious)
A
B
What is a mineral?
• Formed by natural processes such as
cooling magma and evaporating
saltwater
• Inorganic – not made by life processes
• Element or a compound with definite
chemical composition (structure)
• Solid and crystalline (atoms in
patterns that repeat over and over
again)
S.N.I.F.E.
Solid-not liquid, gas, or plasma
Naturally Occurring-Not manmade
Inorganic–Not alive, never was
Fixed Composition - Same recipe
everywhere, every time
Element or Compound-Not a
mixture
How are minerals
classified?
Minerals are grouped
based on crystal systems.
This means that they are
classified according to
their type of repeated
crystal patterns.
How are minerals identified?
(How can you tell them apart?)
• Hardness
• Luster
• Specific
Gravity
• Streak
• Breakage
• Unique
properties
Hardness
Hardness is determined by
how easily a mineral can be
scratched.
Mohs Scale of Hardness is
used to measure the
hardness of a mineral
Mohs Scale
Hardness Hardness of Common
Objects
Talc (softest)
1
Fingernail
2.5
Gypsum
Calcite
Fluorite
2
3
4
Piece of copper 2.5-3.0
Iron nail
4.5
Glass
5.5
Apatite
Feldspar
Quartz
Topaz
Corundum
Diamond (hardest)
5
6
7
8
9
10
Steel file
6.5
Streak plate
7.0
Flint sandpaper
Spinel (rock shops)
Emery sandpaper
Carborundum sandpaper
Luster
The way a mineral
reflects light.
Metallic or Nonmetallic
Specific Gravity
The weight of the mineral
in comparison to the
weight of an equal volume
of water
Streak
The color of a mineral when
it is in powdered form.
Tested by streaking the
mineral across another
object (object must be
harder than the mineral)
Breakage
Clevage-breaks along smooth,
flat surfaces
Fracture-breaks with an
uneven, rough, or jagged
surface
Unique Properties
Many minerals have unique
characteristics that can also
be used to identify the
mineral.
Example-natural magnet,
double refraction, odor,
taste, reaction to acids,
fluorescence, etc.
Uses of Minerals
• Minerals are a component of everyday life
because they are a part of everyday objects
• Jewerly (gems-rare minerals)
• Diamonds are used in industrial abrasives and
cutting tools
• Some minerals are used to produce specific
types of laser light
• Quartz is used in electronics
• Minerals that contain useful substances can be
mined (Ex. Bauxite-aluminum; Ilemenite and
Rutile-titanium)