Transcript Minerals-2011(2)

Minerals
Minerals are all around us
Today you will learn
•What the characteristics of minerals are
•How minerals are classified into groups
•Which mineral group is most common
Fascinating Fact
The elements oxygen, silicon, aluminum, iron,
magnesium, calcium, potassium, and sodium
make up 75 percent of all minerals on Earth.
Just a box of rocks
BACKGROUND:
Scientists have identified over 2000
different minerals in the earth's crust.
75% of the earth's crust is composed of
about a dozen different rock-forming
minerals.
The rocks composed of these minerals can be
formed in three different ways. Scientists
can learn many different things about a rock
by observing and classifying it.
What is a mineral?
Naturally occurring solid formed
from elements or compounds in
Earth’s crust
All minerals are inorganic
Minerals are the building blocks
of rocks
What is a mineral?
A mineral may be an element or a
compound
Mineral
Formula
Gold
Au
Silver
Ag
Copper
Cu
Quartz
SiO2
Galena
PbS
Metal Minerals
Aluminum, iron, copper, and silver are
examples of metal minerals
Recovered for use are called mineral
resources
Useful- stretched into wire, flattened
into sheets, hammered
Figure 2-14 pg. 47
Mineral characteristic #1
occurs naturally
not artificial or manmade
Mineral characteristic #2
Solid
not a liquid or a gas
Platinum
(It might take two billion tons of
ore to produce one pound of
platinum!)
Mineral characteristic #3
Definite chemical
composition
Some minerals like gold
or silver are made of
only one element.
Other minerals, like
quartz and calcite, are
combinations of two or
more elements.
Mineral characteristic #4
atoms arranged in an
orderly pattern
Minerals are usually
solid crystals. They
have a number of flat
surfaces in an orderly
arrangement. For
example, a crystal of
quartz is always
hexagonal because of
the way the atoms of
silicon and oxygen join
together.
Mineral characteristic #5
Inorganic - not
alive and never
alive
SNIFE
Solid
Not Liquid or Gas or Plasma
Naturally Occurring
Not Human-Made
Inorganic
Not Alive - Never Was
Fixed Composition
Same Recipe, Everywhere, Every Time
Element or Compound
Not a Mixture
Identifying Minerals
Physical properties- characteristics
that can be observed or measured
Describe the physical properties of
iron.
Other physical properties
- color, streak, luster, hardness
Color and Streak
Many minerals are the same color
Some are more than one color
Ex. Quartz- purple, yellow, pink, or
colorless
Malachite is always green
Azurite is always blue
Streak
Streak- color of the powder left by a
mineral
Streak of a mineral will always be the
same for that mineral
Chalk is made from the mineral calcite
Leaves a white powder behind
CaCO3
Luster
The way a mineral’s surface reflects
light
Metallic or nonmetallic luster
Metallic will shine like new coins
Nonmetallic will look waxy, glassy, or
dull
Hardness
Hardness- relates to how much it
resists being scratched
Moh’s scale ranks ten minerals in
hardness
High number can scratch any mineral
that has a low number
Lower number cannot scratch a mineral
with a higher number
Moh’s Hardness Scale