Download Mineral Groups in the Earth`s Crust

Definition of “Mineral” pg. 32
Minerals are the building blocks of rocks.
• Must exhibit specific characteristics:
1. Must occur naturally.
2. Must be inorganic ( not from living organisms)
3. Must be solid.
4. Must have a crystal structure
5. Must have a definite chemical composition
( chemical formula)
What Is A Mineral?
A naturally occurring, inorganic solid with a definite
chemical composition and molecular structure. The latter
two is what gives a mineral a set of unique properties.
Minerals can consist of elements (i.e. native elements) or
compounds. The majority of minerals are compounds.
Examples include galena (PbS) and pyrite (FeS2).
Native Minerals consist of only one type of element.
Examples include Gold (Au), Silver (Ag), Sulfur (S),
Diamond (C), Copper (Cu).
To be a mineral, a substance must satisfy the following:
1) Occur in nature
2) Inorganic
3) Solid
4) Definite chemical composition
5) Definite molecular structure
• Explain why or why not synthetic diamonds
could be classified as a mineral.
• Explain why or why not gas, oil, and coal
could be classified as a mineral.
Mineral Groups
Nearly 4000 minerals have been discovered and named;
however, no more than a few dozen are abundant. These
few dozen makes up most of the rocks that comprise
Earth’s crust. This is why we call them the rock-forming
minerals.
Minerals that form the rocks within Earth’s crust
belong to seven (7) main mineral groups, which include:
1) Silicates
2) Carbonates
3) Sulfates
4) Oxides
5) Halides
Reference:
6) Sulfides
Tarbuck and Lutgens
7) Native Elements
Pages 44 - 55
Do You Remember?
• Do you remember the eight elements that
make up more than 98 % of Earth’s crust
(i.e. continental crust)? List them.
• Which two elements are most abundant in
Earth’s crust? Oxygen and Silicon.
• Both comprise nearly three-fourths of
Earth’s continental crust. Both elements
combine to form the framework of the most
common mineral group (i.e. the silicates).
• The framework is called the silicon-oxygen
tetrahedron.
Mineral groups
Hints!
Hints To Classify Mineral Groups
Mineral groups that end
with “ate” and have an
oxygen group in its
chemical formula are one
of the following;
Silicates = Si + Oxygen
Olivine (Mg,Fe)2SiO4
Sulfates = S + Oxygen
Barite
Carbonates = C + Oxygen
Calcite CaCO3
BaSO4
Hints to Classify Mineral Groups
Mineral groups that end
with “ide” and have a
metal (e.g., Na, K) in its
chemical formula are one
of the following;
Oxides = Metal + O
Sulfides = Metal + S
Halides = Metal + Cl, Br, F
Hematite Fe2O3
Pyrite
Fluorite
FeS2
CaF2
Mineral Groups
1) Silicates
 A mineral group that has silicon and oxygen as part .
of their atomic structure. (SiOx)
 Comprise more than 96% of the crust (most common
mineral group).
Rock forming silicates are divided
into two groups:
Sialic Silicates (Aluminosilicates)
Examples include:

Rich in silicon and aluminum.
Quartz

Comprise about 85% of the silicates in the
crust.
Mica (Muscovite)

Mineral are light in color.
Feldspar
Mineral Groups
1) Silicates (Continued)
Simatic Silicates

Rich in silicon and magnesium.

Comprise less than 15% of the silicates in the
crust.

Minerals are dark in colour.
Examples include:
Olivine
Pyroxene
Amphibole
Mineral Groups
2) Carbonates
 compounds consisting of an atomic structure
of one carbon and three oxygen (CO3).
 most common carbonate mineral is calcite (Ca
CO3), which makes up the chemcial sedimentary
rock called limestone as well as the metamorphic
rock called marble.
3) Sulfates
 compounds consisting of an atomic structure
of one sulfur and four oxygen (SO4).
 the rock gypsum is an example of a sulfate and it
also takes on the mineral name. (CaSO4 • 2H2O)
The mineral barite (BaSO4) is mined and used in
drilling mud.
Mineral Groups
4) Oxides
 compounds consisting of an atomic structure
of oxygen combined with one or more metals.
 most common oxides are those of iron (Fe2O3) and
aluminum (Al2O3); referred to as the Ore Minerals.
As an example, the mineral hematite is Fe2O3
5) Halides
 compounds consisting of an atomic structure of chlorine
(Cl), bromine (Br) or fluorine (F) with sodium, potassium,
or calcium.
 Halite (NaCl) is the most common halide. It is
often referred to as table salt.
Mineral Groups
6) Sulfides
 compounds consisting of an atomic structure
of one or more metals combined with sulfur.
 examples of minerals include: pyrite (FeS2), galena
(PbS), and sphalerite (ZnS).
7) Native Minerals
 elements that occur uncombined in nature.
 commonly called native elements.
 examples include: gold (Au), silver (Ag), copper
(Cu), and sulfur (S).
NOTE
• Note that an ore mineral is any mineral that
has enough of a particular element in it to
be mined at a profit.
Sample Problem
Which is an example of a halide?
(A)
(B)
(C)
(D)
barite (BaSO4)
calcite (CaCO3)
fluorite (CaF2)
hematite (Fe2O3)