A Compound is…..
A substance made from
two or more different
elements that have
been chemically
combined.
A Mixture, on the other hand, is…
A substance made from two
or more different elements
that have not been chemically
combined, and which can be
separated by physical means
A Mineral is a naturally occurring
Inorganic Solid with a definite
chemical composition and a
crystalline structure.
That means that…
•It can’t be organic in
origin
•It can’t be a liquid
and..
•It has to have a crystal
structure
5 Characteristics of minerals are:
1. Inorganic
2. Solid
3. Occurs Naturally
4. Definite Chemical Composition
5. Atoms are arranged in an orderly
pattern
Rocks that have a high percentage
of Silicates are light in color, and
are called Felsic rocks.
Rocks that have a low
percentage of Silicates are dark
in color, and are called
Mafic rocks.
How do Minerals Form???
1. Minerals form in cooling magma chambers
Different types of minerals crystallize at
different temperatures
Decreasing temperature
Bowen’s Reaction Series
Mineral formation in a Magma Chamber
Also the size of the mineral crystals is
determined by the rate of cooling of the
magma.
-Large crystals form when the magma cools
very slowly.
-Small crystals form when the magma cools
very quickly.
Olivine
Peridotite- Mostly Olivine
Pyroxene
Gabbro- Pyroxene and Olivine
Gabbro- Pyroxene and Olivine
Pyroxene
2. Metamorphic Minerals:
Some minerals occur as the result of
Recrystallisation and Reaction within
existing rocks which produces new
minerals in response to changes in
and
Pyroxene
3. Some types of minerals form as
water containing dissolved ions
slowly evaporates.
Salt deposits
A Crystal is….
A regular geometric solid with smooth
surfaces called….
Minerals are identified and
classified by visual inspection, and
by performing simple tests to
determine their physical properties
Color is the most easily observed, but least
reliable property of a mineral for identification.
This is because the color of many minerals
varies with the kind of impurities in the mineral.
Streak is the color of the powder left on
a streak plate when a mineral is rubbed
on it.
Streak is much more reliable than
color because, although the color of
a mineral changes, its streak does
not.
Luster is the way in which a mineral shines in the light.
Cleavage is the tendency of a mineral
to split in a particular direction.
Fracture is the tendency of a mineral to
break in directions other than along crystal
faces or cleavage surfaces.
Hardness is the resistance of a mineral to
being scratched.
The Mohs Hardness Scale is one of the
most effective tool for identifying
minerals.