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Groups of Minerals. Mineral Groups - Notes. As you view the slides, write your notes into the graphic organizers. Include all the information from each slide into the appropriate boxes. Write neatly and carefully.
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Mineral Groups - Notes • As you view the slides, write your notes into the graphic organizers. • Include all the information from each slide into the appropriate boxes. Write neatly and carefully. • You will not be expected to memorize this information, but this information will be used as a reference throughout our mineral unit and help you become familiar with the different types of minerals that exist.
Mineral Groups • Minerals are divided into groups based on their chemical composition • The two main groups all minerals can be classified into are: • Silicates • Nonsilicates
Silicates • Mineral formulas end in (Si) and Oxygen (O) • Example: SiO4 • Composed of silica tetrahedrons • Make up 90% of the Earth’s crust • Combine with elements such as Aluminum (Al), Iron (Fe), Magnesium (Mg), and Potassium (K)
Silicates - Groups • Nesosilicates • “Island” silicates • Individual silica tetrahedrons packed together • Garnet - A3B2(SiO4)3
Silicates - Groups • Sorosilicates • Bowtie silicates • Two silica tetrahedrons together • Hemimorphite • Zn4(SiO4)
Silicates - Groups • Cyclosilicates • Ring silicates • Silica tetrahedrons form rings. • Beryl • Be3Al2(Si6O18)
Silicates - Groups • Inosilicates • Chain silicates • Silica tetrahedrons link together to form long chains • Hornblende • (Ca,Na)2(Mg,Fe,Al)5(Al,Si)8O22 (OH)2
Silicates - Groups • Phyllosilicates • Sheet silicates • Silica tetrahedrons form sheets • Soft • Biotite K2(Mg,Fe)3AlSi3O10(OH,O,F2)2
Silicates - Groups • Tectosilicates • Framework silicates • Repeatedly stacked silica tetrahedrons • Quartz • SiO2
Nonsilicates • Do not contain a combination of Silicon (Si) and Oxygen (O) in their chemical composition • There are 6 groups of nonsilicates: • Native Elements • Oxides • Carbonates • Sulfates • Halides • Sulfides
Native Elements • Minerals composed of only one element • Examples are: • Gold (Au) • Copper (Cu) • Silver (Ag)
Oxides • Mineral formulas end with Oxygen (O) • Some elements that bond with O are Aluminum (Al) and Iron (Fe) • Most are black or dark grey, but some are colorful. • Generally above average hardness • Examples of oxides: • Chromite - FeCr2O4 • Hematite - Fe2O3
Carbonates • Mineral formulas end with Carbon and Oxygen (CO3) • Typically transparent or lightly colored with a white streak • Soft, above average density • Obvious cleavage • Examples: • Calcite - CaCO3 • Malachite - Cu2CO3(OH)2
Sulfates • Mineral formulas end in Sulfur and Oxygen (SO4) • Typically vitreous with average to high density • Average hardness • Examples: • Gypsum - CaSO4.2H2O • Barite - BaSO4 • Celestite - SrSO4
Halides • Mineral formulas most often end in Chlorine (Cl) or Fluorine (F) • Low density • Typically soft and transparent • Have good cleavage and bright colors • Examples: • Halite - NaCl • Fluorite - CaF2
Sulfides • Mineral formulas end in Sulfur (S) • Metallic with dark colored streaks • High density and are soft • Examples: • Galena - PbS • Pyrite - FeS2