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Normal Matter is composed
of…….
Atoms differ in the number of
“pieces” ( Protons, Neutrons and
Electrons) that they have inside of
them.
Atoms with certain consistent
characteristics are called….
matter that is made up of
atoms…
atoms
(or one atom) that
have the same number of
Protons in their nucleus.
But!!!
Not all atoms of the
same element are the
same, either.
Atoms of the same element that
have different numbers of
neutrons in their nuclei are
called….
Certain isotopes of elements are
unstable, or radioactive.
(example: Carbon-14 and
Uranium-238)
These radioactive isotopes of
elements allow us to do absoluteage dating!
Most substances on Earth are
not pure elements but rather….
???
What is a Compound?
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
Elements by
themselves are much
less common than
Compounds, but they
do exist.
Elements and Compounds in their
solid form make up…
What is a Mineral?
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
How many different minerals are
there on Earth???
Answer:About 4,000
More than 90% of all of the
minerals in the Earth’s Crust are
made up of compounds
containing Silicon and Oxygen,
the two most abundant elements
on Earth.
And…..
The percent composition of Silicate in
magma determined a lot of the
characteristics of the minerals and
ultimately the rock that forms.
High Silica content forms lightcolored rocks.
While lower (but only by about
25%) Silica content forms
darker-colored 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
Pyroxene
Peridotite- Mostly Olivine
Gabbro- Pyroxene and Olivine
Andesite- Hornblend and Biotite? and
Plagioclase Feldspar
Potassium Feldspar
Quartz
Pink Granite
Mineral Fractionalization in a Magma Chamber
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
3. Some types of minerals form
as water containing dissolved
ions slowly evaporates.
Salt deposits
How long does it take for
minerals to form??
• Minerals in solution in water can form
relatively quickly when the water
evaporates.
• Minerals in magma can form as quickly as
the magma/lava can crystallize (lava can
cool in minutes, while magma can take
thousands of years).
A Crystal is….
A regular geometric solid with
smooth surfaces called….
The orderly arrangement of ions,
molecules, or atoms, in any
mineral determines the shape of
its crystals.
Although there are thousands of
different types of minerals, their
crystals come in six basic types
of shapes
Minerals are most often
identified by inspecting their
Physical and Chemical
properties.
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.
Types of Luster
Cleavage is the tendency of a mineral
to split in a particular direction.
“Sheety” Cleavage
Feldspars always cleave readily at or near right angles.
Fracture is the tendency of a
mineral to break in directions other
than along crystal faces or cleavage
surfaces.
Conchoidal or shell-like fracture
Fibrous facture
Hardness is the resistance of a mineral to
being scratched.
The Mohs Hardness Scale is one of the
most effective tool for identifying
minerals.
Only 30 of the 4,000 known
minerals are common.
These 30 minerals are known
as the rock-forming minerals
Most rock-forming minerals
are…
The percent composition
of Silicate minerals in a
rock determines the type
of rock it is.
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.
Rocks are often made of several
different minerals.
Other Rock-Forming mineral groups are:
• Carbonates
• Oxides
• Sulfides