Minerals form by natural geological processes and have distinct physical properties that allow them to be identified and classified. They are solid, naturally occurring inorganic substances with a definite chemical composition and crystalline structure (atoms arranged in repeating patterns). Key properties used to identify minerals include their color, hardness, luster, density/specific gravity, streak, breakage patterns, and unique characteristics. Minerals have many important uses from jewelry to industrial applications.

1. Minerals

2. What is the difference in picture A
and B? (Other than the obvious)
A B

3. What is a mineral?
• Formed by natural processes such as
cooling magma and evaporating
saltwater
• Inorganic – not made by life
processes. Not alive.
• Element or a compound with definite
chemical composition (structure)
• Solid and crystalline (atoms in
patterns that repeat over and over
again)

4. 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

5. 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.

6. How are minerals identified?
(How can you tell them apart?)
• Color
• Hardness • Streak
• Luster • Breakage
• Specific • Unique
Gravity properties

7. Color
• The appearance of color of a mineral.
• Minerals can also change colors when
they react with air or water.
• Color is NOT very reliable for identifying
minerals because colors can vary greatly
and are not consistent.
• Streak tests are much more reliable.

8. 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

9. Mohs Hardness Scale
Mohs Scale Hardness Hardness of Common
Objects
Talc (softest) 1 Fingernail 2.5
Gypsum 2 Piece of copper 2.5-3.0
Calcite 3 Iron nail 4.5
Fluorite 4 Glass 5.5
Apatite 5 Steel file 6.5
Feldspar 6 Streak plate 7.0
Quartz 7 Flint sandpaper
Topaz 8 Spinel (rock shops)
Corundum 9 Emery sandpaper
Diamond (hardest) 10 Carborundum sandpaper

10. Luster
The way a mineral
reflects light
(dull or shiny).
Metallic or Nonmetallic

11. Density
• D=M/V -g/cm3
• Is a measure of how much matter is in a
given object.

12. Specific Gravity
The Density of the
mineral in comparison to
the Density of an equal
volume of water (1g/cm3).

13. • -Ex: Gold’s density is 19g/cm3. What is
its Specific Gravity?
• SG=19g/cm3 divided by 1g/cm3
• SG=19

14. 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)

15. Breakage
Clevage-breaks along smooth,
flat surfaces
Fracture-breaks with an
uneven, rough, or jagged
surface

16. 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.

17. 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)