Classification of Minerals

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Classification of Minerals
Native Elements minerals naturally composed of
only one element (e.g., diamond, sulfur,
gold) Sulfides and Sulfates minerals containing
SO4-2 or S-2 anions (e.g., galena, pyrite,
gypsum) Oxides minerals containing O-2 anions
(e.g., hematite, magnetite, rutile) Silicates
huge family of minerals which all contain some
variant of SiO2 (e.g., quartz, garnets, micas,
feldspars, clay minerals). Carbonates minerals
containing the CO3 anion (e.g., calcite,
barite) Others including salts (fluorite,
halite), and a several other groups.
Dana Classification System, the complete list of
known minerals has 78 categories
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Most Common Elements in Earths Crust
O
Al
Si
Na
Mg
Fe
K
Ca
Oxygen
Aluminum
Potassium
Sodium
Silicon
Calcium
Magnesium
Iron
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Common Rock Forming Minerals
Percent of atoms in Earths crust
6.2
20.5
60.5
O
Si
Al
Fe
Na
K
Mg
Ca
Quartz Plagioclase feldspar Potassium
feldspar Pyroxene Group Amphibole
Group Muscovite Biotite
SiO2
Si
O
O
Si
Al
Ca
Na
AlSi3O8
K
O
Si
Al
Al2Si2O8
O
Si
Fe
Ca
Na
Mg
SiO3
O
Si
Fe
Mg
Si8O22
K
O
Si
Al
AlSi3O10(OH)2
K
O
Si
Al
Fe
Mg
AlSi3O10(OH)2
These minerals make up more than 90 of the
Earths crust. All are silicates
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Other Important Rock Forming Minerals
Calcite - major component of limestone and
seashells, 3 on Mohs Hardness Scale
Dolomite - major component of limestone
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Other Important Rock Forming Minerals
Clay minerals basis of most soils
Gypsum very common evaporite in arid
environments, used for plaster and drywall, 2
on Mohs Hardness Scale
Halite common evaporite in arid environments,
dietary staple
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Other Important Rock Forming Minerals
Hematite major ore mineral of iron
Magnetite major ore mineral of iron
Galena major ore mineral of lead
Sphalerite major ore mineral of zinc
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Other Important Rock Forming Minerals
Olivine useful for interpreting igneous rock
formation
Garnet group useful for interpreting
metamorphic rock formation
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Minerals form wherever and whenever the molecular
building blocks are present and local conditions
allow those building blocks to bond. Local
conditions can change dramatically in all of
Earths mineral-forming environments (both on the
Earths surface and within the Earth), making for
interesting mineral associations. The rock types
(igneous, sedimentary, metamorphic) are defined
by the conditions under which they formed.
Evaporite minerals with collector
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