Download Minerals

Minerals
And Their Properties
Minerals
In order to be a mineral a substance must meet
5 criteria:
1. Inorganic (not part of or produced by living
things)
2. Occur naturally in or on the earth
3. Solid
4. Atoms are arranged in an orderly pattern
5. It has a definite chemical composition
Minerals

There are about
4000 minerals
 Liquid water, coal
are examples on
non minerals
Minerals found on the Earth’s
crust
Common minerals found are quartz,
mica, feldspar (3 types) and calcite
 Rare minerals, such as gold and
diamonds are also found

Mineral Composition
Most minerals are compounds, made up
of more than one element
 Oxygen and Silicon are the two most
common elements found in minerals

Mineral Formation

Minerals are
formed by two
processes
1. Magma process
Magma rises from
deep within the
Earth. The
particles in the hot
magma move
freely
Magma Process cont
2.
3.
When the magma begins to cool,
atoms, molecules and ions move
closer together and bond to form
various compounds
Over time, molecules of the compound
mass together as grains of minerals
Pressure Process

When a rock is subject to high temperatures
and pressure, the minerals can break down
chemically
 The temperature and pressure becomes
great enough to change the minerals in a
solid state, without melting them
 The free atoms, ions and molecules
recombine to form new minerals. Mineral
growth occurs away from the pressure
Crystals

Remember minerals
have atoms that
arrange in orderly
patterns
 A crystal is a solid
substance in which
the orderly pattern
repeats over and
over again
Silicate

Silicates are minerals that are made up
of silicon and oxygen. These minerals
may also contain other elements.
Mineralogy
Mineralogy is the study of minerals and
their properties
 Rock forming minerals are minerals
found on the Earth’s crust that make up
most of the rocks

Identifying Minerals
Use properties that result from their
unique chemical make up
Color- easy to observe but…..
 Lots of minerals have the same color
 Color can be changed by weathering or
impurities

Identifying Minerals

Luster – How shiny
a mineral is
a. Metallic- shines
like a polished metal
Identifying Minerals

Luster – non
metallic – 3 types
1. Vitreous –glassy
2. pearly
3. dull
Mineral Identification
Crystal shape –
given proper
conditions crystals
will form in one of
six different shapes.
 Each mineral will
form only one shape
because of the way
the atoms and ions
combine

Mineral Identification
Streak – the color of the mineral in
powder form as seen on a streak plate.
 More reliable than the general color of
the mineral because it seldom varies

Mineral Identification

Cleavage or Fracture – haw a mineral
breaks
1. Cleavage – tendency to split along
flat surfaces
2. Fracture – uneven breakage leaving
rough edges
Mineral Identification
Hardness – how hard a mineral is on
Moh’s s scale. Made by Fredrick Moh.
 Diamond the hardest; graphite the
softest. Both made of only carbon

Mineral Identification
Density – each mineral has a unique
density
density = mass
volume
 Metallics have high density, nonmetallics have low density

Mineral Identification
Acid test – reaction between mineral
and acid where CO2 bubbles are
produced
 Only seen in carbonates

Mineral Identification

1.
2.
3.
4.
Special Properties-not seen in most
minerals
Magnetism – attracted to magnets
Taste – we do not use this here
Fluorescence – Glows in UV light
Radioactivity – produces heat (not
good to handle)