REVIEW FOR GEOLOGY 141

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REVIEW FOR GEOLOGY 141 CHEMISTRY WHIZ SHEET
(Follow along on p. 61)
If one knows the chemical formula for a
particular mineral, with a little help from this
sheet, one could determine which mineral group
it belongs to without a lot of rote memorization,
as follows
Colby Geology
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OXIDES
CORUNDUM
If a mineral formula ends with Ox, like Specular
Hematite and Oolitic Hematite (Fe2O3), Magnetite
(Fe3O4) or Corundum (Al2O3), then that mineral
belongs to the OXIDE group.
MAGNETITE
SPECULAR HEMATITE
OOLITIC HEMATITE
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HYDROXIDES
If a mineral formula ends with OH, like Limonite
(FeOOH) or Bauxite, then that mineral belongs to
the HYDROXIDE group.
BAUXITE
LIMONITE
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SULFIDES
If a mineral formula ends with Sx, like
Chalcopyrite (CuFeS2), Galena (PbS), Pyrite
(FeS2) or Sphalerite (Zn,FeS), then that mineral
belongs to the SULFIDE group.
SPHALERITE
GALENA
PYRITE
CHALCOPYRITE
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CARBONATES
If a mineral formula ends with CO3, like Calcite
(CaCO3), or Dolomite (Ca,Mg(CO3)2) then that
mineral belongs to the CARBONATE group.
DOLOMITE
CALCITE
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HALIDES
If a mineral formula ends with F, Cl, Br, I,
like Fluorite (CaF2) or Halite (NaCl), then
that mineral belongs to the HALIDE group.
HALITE
FLUORITE
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SULFATES
If a mineral formula ends with or includes SO4,
like gypsum CaSO42H2O, then that mineral
belongs to the SULFATE group.
GYPSUM
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NATIVE ELEMENTS
If a mineral formula is a single element, like
Native Copper (Cu), then that mineral belongs to
the NATIVE ELEMENTS.
GOLD
COPPER
SILVER
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SILICATE MINERALS
The remainder of the minerals belong to the
SILICATE Group, and the respective subgroup
depends on how the silica tetrahedra (SiO4) are
attached within the mineral.
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FRAMEWORK SILICATES
FRAMEWORK SILICATES include Orthoclase
(KAlSi3O8), Oligoclase and Labradorite (Ca,Na)
(Al,Si)4O8 and Quartz (SiO2). SiO ratio 12
FELDSPAR
QUARTZ (SiO2)
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SHEET SILICATES
SHEET SILICATES include Biotite, Chlorite and
Muscovite.
MUSCOVITE
BIOTITE
12
CHAIN SILICATES
SINGLE CHAIN SILICATES include Augite. SiO ratio
13
AUGITE
13
CHAIN SILICATES
DOUBLE CHAIN SILICATES include Actinolite and
Hornblende. SiO ratio 12.75
ACTINOLITE
HORNBLENDE
14
ISLAND SILICATES
ISLAND SILICATES include Garnet, Olivine
(Fe,Mg)2SiO4 and Staurolite. SiO ratio 14
OLIVINE
STAUROLITE
GARNET