Minerals
What is a
mineral?
 Solid
 Not a liquid or gas
 Naturally Occurring
 Found in nature, not man-made
 Inorganic
 Is not alive and never was, nonliving
 Fixed composition
 Has a chemical formula, most
are formed from compounds of
two or more elements, some
minerals consist of one element
ex. Au, FeS
 Crystal Form
 A definite structure in which
atoms are arranged
Define a
mineral.
• A mineral is a naturally
formed, inorganic solid
that has a definite
crystalline structure.
How can I
• Is it non-living material?
determine it
• Is it a solid?
is a mineral?
• Is it formed in nature?
• Does it have a crystalline
structure?
Please make this chart below
• Minerals
• Non-Minerals
Wood
Gold
Fossil
Topaz
Bones
Granite
Quartz
Pearls
Talc
Ice
Diamond
Coal
Rock Salt
And the answers are…
• Minerals
a)
b)
c)
d)
e)
f)
Gold
Topaz
Quartz
Talc
Iceberg
Diamonds
• Non-Minerals
a)
b)
c)
d)
e)
f)
g)
Wood - once living
Fossils – once living
Bone - living material
Granite - intrusive igneous rock
Pearls – made by oysters
Coal - Sedimentary rock
Rock Salt – Sedimentary rock
Identifying Minerals
What
properties
identify
minerals?
•
•
•
•
•
•
•
•
Color
Streak
Luster
Density
Hardness
Crystal System
Cleavage and fracture
Special Properties
What
properties
identify
minerals?
• Color – a physical property
– Often not enough info.
PYRITE
GOLD
CHALCOPYRITE
What
properties
identify
minerals?
• Streak – color of its powder.
– Test – drag across porcelain tile
– Often different than color
Streak plate showing magnetite with gray streak (left)
and hematite with reddish-brown streak (right). Photo
by M. Minitti, ASU/CMS.
What
properties
identify
minerals?
• Luster – describes how light is
reflected from a mineral’s
surface.
– Metallic, Sub Metallic, Glassy,
Silky, Waxy/Greasy, Earthy
What
properties
identify
minerals?
What
properties
identify
minerals?
• Density – mass per volume
– Can compare by picking up like
sized pieces
What
properties
identify
minerals?
• Hardness – can it scratch or is
it scratched by another
mineral.
– Test – scratch test
• Mohs Hardness scale
– Ranks 10 minerals
– Talc, gypsum, calcite, flourite,
apatite, feldspar, quartz, topaz,
corundum, diamond.
• What if the mineral isn’t on
the list
– Try scratching one that is.
HOW MINERALS
FORM?
How do
minerals
form?
• Crystallization – The
process by which atoms are
arranged to form a material
with a crystal structure
Two ways
that
minerals
form?
1. Crystallization of magma
and lava
2. Crystallization of
materials dissolved in
water
Two ways that
minerals
form?
• Magma cools inside the crust
and lava cools on the surface
– Both will form crystals
• Size of crystals depends on:
– Rate of cooling
•
Slow = large crystals
– Amount of gas
– Chemical composition
Two ways that
minerals
form?
• Minerals dissolved in solutions
• Evaporation
– When a solution with minerals
dissolved in it evaporates the
crystals are left behind
•
Halite, Gypsum, Calcite
• Hot water solutions
– Magma heats water , minerals
dissolve, water cools and
minerals crystallize.
– Metals dissolve and flow
through rocks to form veins.
Uses of Minerals
Describe
• Gemstones
three uses
– Rubies, sapphires
of minerals.
• Metals
– Aluminum, iron, copper, silver,
gold
• Other
– Food , Medicines, Fertilizers,
Building Materials
Describe
the
processes
used to get
minerals.
• Metals  Minerals
• Remove rock from ground
containing mineral.
• Process to extract mineral or
Ore.
• Ore – rock that contains metal
or useful mineral that can be
mined and sold for profit
Describe
the
processes
used to get
minerals.
• Prospecting – looking for ore
deposits.
– Studying maps to find where
ores may occur
• Mining – removing ore from
ground
– Strip mines – scrape soil to
expose ore
– Open pit mines – huge pit to
find ore
– Shaft mines – network of
tunnels following veins of ore.
Describe
the
processes
used to get
minerals.
• Smelting – ore is mixed with
other substances and then
melted to separate useful
metal or element.
• Removing impurities
• May add other things to make
• Alloys – solid mixture of two
or more elements
Describe
the
processes
used to get
minerals.