Download Mineral Groups in the Earth`s Crust

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.
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.
 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
or fluorine 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)