SILICATE VS. NON-SILICATE CLASSIFICATION OF...
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11/9/2016 1 SILICATE VS. NON - SILICATE CLASSIFICATION OF MINERALS ALL MINERALS ON EARTH FALL INTO ONE OF THESE CLASSIFICATIONS TWO MAIN DIVISIONS OF MINERALS (SILICATE AND NON - SILICATE) SILICATES (95 % OF EARTH’S CRUST) • • Silicate Types: • • Feldspar • Orthoclase Feldspar (KAlSi 3 O 8 ) • Plagioclase Feldspar (NaAlSi 3 O 8 CaAl 2 Si 2 O 8 ) • • Hornblende (Ca 2 Fe 5 Si 8 O 22 F 2 ) • Olivine Fe 2 SiO4 • Muscovite (KAl 2 (AlSi 3 O 10 )F 2 ) • Biotite (KMg 3 AlSi 3 O 10 (OH) 2 ) NON-SILICATES (5% OF EARTH’S CRUST) • DO NOT CONTAIN SILICON!!! • Carbonates – contain carbonate (CO 3 ) • Calcite (CaCO 3 ) • Dolomite (CaMg(CO 3 ) 2 ) • • Gypsum (CaSO 4 ) • Halides – contain (Cl, F with Na, K, Ca) • Halite (NaCl) • Fluorite (CaF 2 ) • Oxides – contain oxygen (O) and NOT silicon (Si) • Hematite (Fe 2 O 3 ) • Magnetite (Fe 3 O 4 ) • Native Elements – uncombined with other elements • Silver (Ag) • Copper (Cu) • • Galena (PbS) • Pyrite (FeS 2 )
Transcript of SILICATE VS. NON-SILICATE CLASSIFICATION OF...
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SILICATE VS. NON-SILICATECLASSIFICATION OF MINERALS
ALL MINERALS ON EARTH FALL INTO ONE OF THESE CLASSIFICATIONS
TWO MAIN DIVISIONS OF MINERALS(SILICATE AND NON-SILICATE)
SILICATES (95 % OF EARTH’S CRUST)
• Contain silicon (Si) and oxygen (O)
• Silicate Types:
• Quartz (SiO2)
• Feldspar
• Orthoclase Feldspar (KAlSi3O8)
• Plagioclase Feldspar (NaAlSi3O8 CaAl2Si2O8)
• Ferromagnesian Minerals
• Hornblende (Ca2Fe5Si8O22F2)
• Olivine Fe2SiO4
• Muscovite (KAl2(AlSi3O10)F2)
• Biotite (KMg3AlSi3O10(OH)2)
NON-SILICATES (5% OF EARTH’S CRUST)
• DO NOT CONTAIN SILICON!!!• Carbonates – contain carbonate (CO3)
• Calcite (CaCO3)• Dolomite (CaMg(CO3)2)
• Sulfates – contain sulfate (SO4)• Gypsum (CaSO4)
• Halides – contain (Cl, F with Na, K, Ca)• Halite (NaCl)• Fluorite (CaF2)
• Oxides – contain oxygen (O) and NOT silicon (Si)• Hematite (Fe2O3)• Magnetite (Fe3O4)
• Native Elements – uncombined with other elements• Silver (Ag)• Copper (Cu)
• Sulfides – contain sulfur (S)• Galena (PbS)• Pyrite (FeS2)
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SILICA CONTENT AND MINERAL PROPERTIES
SILICA-RICH MINERALS
• Melt at lower temperatures
• Last to crystallize from cooling magma
• More resistance to chemical weathering
SILICA-POOR MINERALS
• Melt at higher temperatures
• Tend to crystallize earlier in cooling magma
• Less resistance to chemical weathering
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silica-rich feldspar silica-poor olivine
USING CRYSTALLINE STRUCTURE TO IDENTIFY MINERALS
• Minerals have an organized distribution of atoms.
• Crystals are an outward display of internal atomic geometry.
• Bond strength affects the minerals resistance to breakdown.
• Basic building block of silicates is the SiO4
tetrahedron.
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TYPES OF SILICATE CRYSTALS AND CHAINS
• ALL SILICATES ARE BUILT WITH THE
SiO4 TETRAHEDRON.
• Tetrahedron Variations1. Independent tetrahedron
family- Olivine
2. Single-chain tetrahedral family (Share 2 oxygen) Ex. Pyroxenes.
3. Double-chain tetrahedral family (2-3 oxygen shared) Ex. Hornblende
4. Sheet tetrahedral family (3 shared Oxygen)Ex. Micas
5. Network family(all 4 Oxygen shared) very strong bondsEx. Quartz
CRYSTAL STRUCTURES OF NON-SILICATE MINERALS
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Crystal FormSome minerals that grow without being impeded by their environment
develop characteristic crystal shapes or crystal form that represents the
symmetry of the crystal structure. Crystal form can be a diagnostic
property for some minerals.
Quartz has an internal structure
that has a 6-sided (hexagonal)
symmetry. As a result, quartz
crystals commonly are 6-sided.
Halite has an internal structure that
has a cubic (4-sided) symmetry. As
a result, halite crystals commonly
are cube shaped.
