Minerals and Their Uses
Minerals You Know
• Can you think of some different types of
– Blue Sapphires
– Red Rubies
– Green Emeralds
– Mineral Graphite (in pencil lead)
– Mineral Copper (used in coins)
There are four conditions that
1.Minerals occur naturally
• Salt deposits formed
naturally is the
mineral halite. Salt
that we use to flavor
food or NaCl is not a
2. Minerals are inorganic
•They are not alive or formed
by anything that was alive.
3. Minerals have unique chemical
– Each type of mineral has a chemical
composition that is unique to that mineral.
For example mineral quartz is a combo of
two elements, Si and O. Other minerals may
contain silicon and oxygen but the
arrangement and proportion
of these elements in quartz
are unique to quartz.
Quartz’s Chemical Formula Topaz’s Chemical Formula
4. Minerals have crystalline
– Atoms in a mineral are
arranged in a regular
geometric pattern repeated
over and over again.
• Some minerals are gems
or also know as a highly priced
mineral that is rare, or difficult to
• What is place that is known for
– A pharaoh’s treasures are easily
known as gems because they
have been cut and polished. If
they were not cut and polished
would you know what to look for?
• What was the California Gold Rush?
This was a time in history when
people left their homes and
families and went in search for
their fortunes. It was a
massive migration of people to
an area where gold was
discovered. It started in Sutter’s Mill in
California in 1848. If you were alive then would
you have been apart of it, if so would you know
what to look for?
Can You Tell the Difference?
One of these pictures is gold the other is not
can you tell the difference?
If you guessed this one
give yourself a pat on Haha Fooled You
the back, you’re right
• We use five characteristic to identify
5.Cleavage and fracture
• When a mineral is rubbed across a streak
plate, a streak is left behind.
• The color of a mineral when it is broken up
and powdered is called its streak.
• Color of a mineral can help to identify what
it is, however you do need more
information. Some minerals that are easy
to identify by color include sulfur and
• Luster refers to the way that a mineral
reflects light. Minerals are divided into to
groups based on their luster, Nonmetallic
Luster and Metallic Luster
Pyrite Mineral-metallic luster Feldspar Mineral-Nonmetallic Luster
• The color, luster, or streak can vary
among samples of mineral. Hardness is a
more useful property to help identify
• Hardness is a measure of how easily a
mineral can be scratched.
• We use the Mohs Scale, named after
Friedrich Mohs who devised it.
• Starts at 1 with Talc which is easily
scratched with your nail moves to 2 and
Gypsum that can be scratched with your
nail at 3 there is Calcite that can barely be
scratched with your finger. It ends at 10
with the diamond that scratches common
materials and is often used to sharpen
Cleavage and Fracture
• Minerals differ in the way they break.
– Minerals that break along a
smooth, flat surfaces have
• Example- Mica
– Minerals that have curved,
rough, or jagged surfaces
when they break apart have
• Example- Quartz
• There are two main ways that minerals form.
– One is the cooling of magma- when magma cools
elements in the magma may form minerals
– The other is formed from elements dissolved in
liquid-When the liquid evaporates the elements
stay behind and may form minerals
Minerals Form from Cooling
• Magma is the hot, molten core beneath
Earth’s crust. It is made up of the same
elements and compounds that make up
• When the magma is forced
up it cools.
• Once cooled the elements
in the magma may
combine chemically and
Slow or Quick
• This cooling process can happen quickly
– If magma cools slowly it form large crystals.
• Mica, feldspar, and quartz have large crystals
–If magma cools
quickly minerals form
small crystals. This
because it is exposed
to air and sometimes
Minerals Form from Water Solution
• Many minerals are made of
more than one element.
Before they become minerals
they are in liquid solution.
• When the water evaporates
the elements may combine in
a mineral’s characteristic