2. After Unit 6 you should be able to:
o Understand how mineral crystals acquire their shape
o Understand the characteristics that define a sample as a mineral
o Understand that many minerals are composed of similar elements
o Understand the connections between minerals and rocks and that
many rocks contain similar minerals
o Utilize the ESRT to determine human uses of common minerals
o Understand and be able to perform common mineral identification
tests such as:
o Color
o Streak
o Breakage (cleavage or fracture)
o Hardness (Mohs Scale)
o Acid test
o Magnetism test
o Luster
o Density
3. o Element
o Atom
o Chemical Composition
o Mineral
o Rock
o Organic
o Inorganic
o Orderly arrangement
o Solidification
o Lava
o Magma
o Igneous
o Precipitate
o Evaporate
o Sedimentary
o Metamorphic
o Crystallize
o Crystal
o Appearance
o Hardness
o Mohs Scale
o Luster
o Metallic
o Non-metallic
o Streak
o Powdered
o Crushed
o Breakage
o Cleavage
o Fracture
o Density
o Mass
o Volume
o Acid
o Reaction
o Magnetic
o Abrasive
o Lubricant
Unit 6 vocabulary you should be able to use and understand:
o Scratch
o Impurities
o Oxidation
o Angular
o Physical properties
o Chemical properties
4. Atoms and Minerals
All matter is made up of atoms
Each atom has particles within it that make it
a specific element such as gold or calcium
Atoms bond together to create molecules
Enough of specific molecules bonded
together form a mineral
Some minerals contain impurities (other
molecules or elements) that change their
properties such as color
5. 5 Fundamental Mineral Characteristics
Definite chemical composition
Orderly arrangement of atoms
Naturally occurring
Inorganic
Solid
6. What is a mineral?
Minerals have a definite chemical
composition unique to that
mineral
Many times the chemical properties
a mineral possesses determines
what humans use that mineral for
For example, the mineral gibbsite
(Al(OH)3) can be processed to
release the aluminum atoms within
it to be used in manufacturing
8. Definite Chemical Composition
The same elements will make up the same
minerals but impurities/oxidation may at
times change their color
For example, table salt, or halite, is always
NaCl…composed of a combination of sodium
(Na) and chlorine (Cl) atoms
9. Other Mineral Uses
Jewelry
Electronics
Abrasives
Lubricants
A source of metal (ore)/other useful
elements
10. What are minerals made up of?
Minerals are composed of 1 or more
elements
Certain elements contribute color to
minerals (such as these quartz
samples), but color alone is not a
definite way of identifying them
Many minerals contain the same
elements
Use your ESRT to identify the
elements after you have determined
the mineral
12. Orderly Arrangement of Atoms
Atoms are arranged in an orderly fashion so
that a crystal forms
This arrangement defines a mineral’s
physical properties such as crystal shape,
hardness, or cleavage
For example: halite crystals and the atoms
that produce them
13. Atomic Arrangement and Breakage
The bonds between atoms (internal atomic
arrangement) in a given mineral determine
how the mineral breaks
Even, angular breakage is known as
cleavage
Uneven, rough breakage is known as
fracture
The cleavage of the mineral graphite allows it
to slide off in sheets when pressure is applied,
thus making it ideal as a material in pencil
lead.
15. How do minerals form?
Minerals crystals form due to one
of several rock-forming processes
found in the rock cycle
Cooling and solidification of
magma/lava
Precipitating out of a solution
Evaporation, leaving the
minerals behind
Undergoing heat and/or pressure
to form new minerals
16. Rocks are made up of 1 or more minerals
This granite has several minerals
within it
17. Identifying minerals can be difficult,
however many minerals can be identified
with a combination of simple tests.
Mineral Identification: Appearance (color)
Color and appearance can help identify
some minerals, but it is usually not
enough
Many minerals have multiple colors
or have the same color as other
minerals
Crystal shape can also help identify a
mineral
Gold
Pyrite
19. Mineral Identification: Hardness
Hardness is a measure of how easily a
mineral can be scratched
Hard minerals are able to scratch
glass while soft minerals do not
Talc is a very soft mineral and can be
scratched by a fingernail
Diamonds are the hardest naturally
occurring material and can only be
scratched by another diamond
20. Mineral Identification: Mohs Scale
The Mohs Scale uses a number to
describe a mineral’s hardness
A diamond is a ’10’ since it is the
hardest mineral
Talc, being one of the softest, is
assigned a ‘1’
Lower numbers more easily
scratched
22. Mineral Identification: Luster
The luster of a mineral describes how
a sample reflects light
Metallic luster is when a mineral
appears to be made of metal
Non-metallic luster can be a variety of
other colors including minerals that
look like glass
24. Mineral Identification: Streak
The streak of a mineral is the powder
left behind when a mineral is crushed
or is rubbed against an unglazed
porcelain tile
26. Mineral Identification: Cleavage and
Fracture
Cleavage and fracture describe how a
mineral breaks caused by the internal
arrangement of atoms
Cleavage is a mineral breaking along
a flat plane
Fracture is uneven and random
breaking
