8th Earth Science
Chapter 3 – Minerals
Name ______________________
Section 1 – Minerals:
Mineral
About _________________ different minerals are found on Earth, but they all share four
characteristics.
1.All minerals are formed by _________________ processes. These are processes that
occur _______or _________________ Earth with no input from humans.
2.Minerals are _________________. This means that they _________________ made by
life processes.
3.Every mineral is an _________________ or compound with a _________________
chemical composition.
4.Minerals are _________________ solids. All solids have a definite volume and shape.
Only a solid can be a mineral, but not all solids are minerals.
The word crystalline means that atoms are arranged in a _________________ that is
_________________ over and over again. For example, graphite’s atoms are arranged in
layers.
Crystal:
A crystal is a group of crystals
that have _________________ atomic arrangements
and therefore similar external crystal
_________________. Not all mineral crystals have
smooth surfaces and regular shapes.
There are __________ major crystal systems,
which classify minerals according
to their crystal structures.
Magma
As magma cools, its atoms lose _________________ energy, move closer together, and
begin to combine into compounds. Atoms of the different compounds arrange themselves
into orderly, repeating patterns. The _________________ and _________________ of
elements present in magma partly determine which minerals will form. When magma cools
slowly the crystals that form are generally _________________ enough to see with the
unaided eye. When magma cools quickly, the crystals that form will be
_________________.
Crystals also can form from minerals _________________ in water. When water
evaporates, as in a dry climate, ions that are left behind can come together to form
crystals.
Or, if too much of a substance is dissolved in water, ions can come together and crystals
of that substance can begin to form in the solution. Minerals can form from a solution in
this way without the need for _________________.
_______elements occur naturally
in Earth’s crust. Approximately
______ percent (by weight) of the crust
is made of only ________ of these
elements. Most of the common
rock-forming minerals belong
to a group called the silicates
Silicates:
These two elements alone combine to form the basic _________________ blocks of most
of the minerals in Earth’s _________________ and _________________.
Section 2 – Mineral Identification:
_________________ and _________________ are two obvious clues that can be used to
identify minerals. Some other properties to study include how _________________ a
mineral is, how it breaks, and its _________________ when crushed into a powder.
Hardness:
Sometimes the concept of hardness is confused with whether or not a mineral will
_________________. It is important to understand that even though a
_________________ is extremely hard, it can _________________ if given a hard blow in
the right direction along the crystal.
In 1824, the Austrian scientist Friedrich _________ developed a list of common minerals to
compare their hardness. This list is called ________ scale of _________________.
Luster:
Luster can be _________________ or _________________. Minerals with a metallic
luster _________________ like metal. When a mineral does not shine like a metal, its
luster is nonmetallic. Terms for nonmetallic luster include _________________, pearly,
_________________, and glassy.
Specific Gravity:
Specific gravity is expressed as a _________________ (with no unit following).
Streak:
When a mineral is rubbed across a piece of unglazed _________________ tile, a streak of
powdered mineral is left behind. The streak test works only for minerals that are
_________________ than the streak plate. Some soft minerals will leave a streak even on
_________________. The last time you used a _________________ to write on paper,
you left a streak of the mineral _________________.
Cleavage:
Cleavage is determined partly by the arrangement of the mineral’s atoms. Not all minerals
have _________________.
Fracture:
_________________ is a mineral with fracture.
Some minerals have unique properties. _________________ is attracted to magnets. Light
forms two separate rays when it passes through _________________ causing you to see
a double image when viewed through transparent specimens.
Section 3 – Uses of Minerals:
Gems:
Most gems are special varieties of a particular minerals. They are _________________,
brighter, or more _________________ than common samples of that mineral.
Sometimes a gem has a crystal structure that allows it to be ______ and
_________________ to a higher quality than that of a non-gem mineral.
All gems are prized, but some are truly spectacular and have played an important role in
_________________.
The _________________ diamond, found in South Africa in 1905, was the largest
_________________ diamond ever discovered. The Cullinan diamond was cut into
_____main stones and ______ smaller ones. The largest of these is called the Cullinan 1
or Great Star of Africa and it is now part of the British monarchy’s _________________
_________________.
Another well-known diamond is the blue _________________ diamond. The Hope
diamond has gained a reputation for bringing its owner _____ luck. The Hope diamond’s
mass is 45.52 _________________. Currently, it is displayed in the _________________
Institute in Washington, D.C.
Diamonds have a hardness of ______ on Mohs scale. They can _________________
almost any material—a property that makes them useful as industrial _________________
and _________________ tools.
Other useful gems include _________________, which are used to produce specific types
of _________________ light. _________________ crystals are used in electronics and as
timepieces. Most industrial diamonds and other gems are _________________ which
means that _________________ make them.
_________________, used in everything from frying pans to ships, is obtained from its
ore, hematite. A mineral or rock is an _________________ if it contains a useful
substance that can be mined at a profit.
Aluminum sometimes is refined, or purified, from the ore _________________. In the
process of refining aluminum, aluminum oxide powder is separated from unwanted
materials that are present in the original bauxite. After this, the aluminum oxide powder is
converted to molten aluminum by a process called _________________.
Under certain conditions, metallic elements can _________________ in fluids. These
fluids then travel through weaknesses in rocks and form mineral deposits. Mineral deposits
left behind that fill in the open spaces created by the weaknesses are called
_________________ mineral deposits.
_________________ is a _________________, _________________, metallic element
derived from minerals that contain this metal in their crystal structures. Two minerals that
are sources of the element titanium are ilmentite and rutile. Titanium is used in automotive
body parts, such as connecting rods, valves, and suspension springs and in
_________________.