Minerals
Chapter 9.1
Minerals
1)Minerals
a)A mineral is a natural inorganic, crystalline
solid found in the Earth’s crust.
i)An inorganic substance is one that is not made
up of living things or the remains of living
things.
ii)Every mineral is unique and can be made up of
a single element such as copper or a compound
of elements such as pyrite.
What is a Mineral?
2) What is a Mineral?
a)There are four main questions to answer
when identifying if a substance is a
mineral or not.
i)Is a substance inorganic?
(1)Coal is organic and not a mineral.
ii)Does the substance occur naturally?
(1)Silver occurs naturally while steel does not.
What is a Mineral?
i) Is the substance a solid in crystalline
form?
(1)Natural gas is not a solid.
ii) Does the substance have a definite
chemical composition?
(1) Halite is made of sodium and chlorine and
has a specific crystalline pattern. While
concrete is made up of several substances, the
amounts of the substances changes depending
on the use of the concrete.
Kinds of Minerals
3) Kinds of Minerals
a)Over 3,000 minerals have been
identified, but fewer than 20 are
common.
i)Out of the 20 common minerals, 10 of
them make up 90% of the mass of the
Earth’s crust.
Kinds of Minerals
b) All minerals can be classified into two main
groups: silicate and non-silicate minerals.
i) Silicate minerals contain atoms of silicon and
oxygen.
ii)While quartz only consists of silicon and oxygen,
most silicate minerals also contain one or more other
elements.
iii)Silicate minerals make up 96% of the Earth’s crust
and 50% of the Earth’s crust is made up of feldspar
minerals.
Kinds of Minerals
c) Non-silicate minerals do not contain silicon.
i) Only 4% of the Earth’s crust is made up of
nonsilicate minerals.
ii)Nonsilicate minerals are classified into six major
groups.
(1)Carbonates
(2)Halides
(3)Native elements
(4)Oxides
(5)Sulfates
(6)Sulfides
Crystalline Structure
4) Crystalline Structure
a)All minerals in the Earth’s crust
have a crystalline structure.
b)Crystalline structures are
characterized by a specific geometric
arrangement of atoms or ions.
Crystalline Structure
c) A crystal is a natural solid with a definite
internal patter.
d)Most of the time this crystalline structure is can
only be seen under a microscope. However,
some crystalline structures can easily be seen
such as calcite, quartz, and halite.
e)There are six crystalline shapes that can form
and help identify minerals.
Crystalline Structure
5) Crystalline Structure and
Silicates
a)While there are many silicate
minerals, they are all made up of the
same basic building blocks.
Crystalline Structure
i)This basic building block consists of four
oxygen atoms arranged in a pyramid with
one silicon atom in the center.
ii)This structure is known as the silicon-oxygen
tetrahedron.
iii)This tetrahedron combines in many
different arrangements to produce the many
silicate minerals.
Tetrahedral Arrangements
6) Types of Tetrahedral Arrangements
a)The isolated tetrahedral silicates contain
tetrahedrons that are linked by atoms
other than silicon and oxygen.
b)Ring silicates for when the tetrahedral
are joined into three, four, or six-sided
rings by oxygen atoms.
Tetrahedral Arrangements
c) In a single-chain silicate, each tetrahedron is
bonded to two others by shared oxygen atoms.
d)In double-chain silicates, two single chains of
tetrahedral bond to each other.
e)In sheet silicates, each tetrahedron shares three
oxygen atoms with other tetrahedra and the
fourth oxygen atom is bonded with potassium
or aluminum which joins one sheet to another.
Tetrahedral Arrangements
f) In a framework silicate, each
tetrahedron is bonded to four
neighboring tetrahedra.
i)The mineral quartz is formed by only siliconoxygen tetrahedrons. However, other
minerals can be formed by replacing the
silicon atom of the tetrahedron with another
element such as aluminum. This creates the
feldspars.