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Physical Geology

Day 3 geology Minerals Building blocks of rocks Host of valuable elements Environmental Matter Solids, liquids, gases and plasmas Made up of chemical elements Mineral A natural occurring, solid, crystalline, inorganic element or compound Occur in nature (not manufactured) Has an ordered arrangement of atoms Inorganic--Not hydrocarbon (oil, etc) Has a definite chemical formula or one that varies within set limits Minerals are chemical compounds, but.. 1. A chemical compound may exist in more than one crystal structure- POLYMORPHIS--same composition, but different lattice--such as diamond and graphite Physical properties Luster - The appearance of the mineral in reflected light Metallic (splendent) Submetallic Vitreous (or glassy) Adamantine (also known as brilliant or diamond-like) Resinous (like tree sap) Silky Pearly Greasy (or oily) Pitchy (kind of waxy?) Waxy Dull (or earthy) Color - Some minerals have a fixed color (quartz can be different colors) Streak - The color of the powdered mineral Fracture or Cleavage - The tendency to break along smooth planes Cleavage can be perfect, or not so good. We also look at cleavage directions. One direction - Muscovite Two directions - Feldspar Three directions - Halite (all at 90 degrees) Three directions - Calcite (not 90 degrees) Hardness - 1 Talc, 2 Gypsum, 3 Calcite, 4 Flourite, 5 Apatite, 6 Orthoclase, 7 Quartz, 8 Topaz, 9 Corundum, 10 Diamond. The gears can fly above our quick turbo convertible drive TGCFAOQTCD The Girls Can Flirt And Other Quaint Things Can Do Crystal form Natural shapes bounded by plane surfaces assumed during formation Hardness (or softness) Double refraction (polarization and split) Conductivity and Resistance - the degree to which a specified material conducts electricity Piezoelectric - ability of certain materials to generate an electric charge in response to applied mechanical stress. Luminescence Fluorescence - glows under a black light Phosphorescence Triboluminescence Common elements in the crust Oxygen 46.8%, Silicon 27.7%, Aluminum 8.1%, Iron 5.0%, Calcium 3.6%, Sodium 2.8%, Potassium 2.6%, Magnesium 2.1%... Oxygen takas up 93.8% of the crust Mineral Compounds Simple compounds - combinations of two elements (cation-anion) i.e. NaCI Complex compounds - compounds containing complex ions Example: Ca C03 Cation Substitution Cations of about the same size may substitute in the make up of a mineral Examples of Minerals as Anion Groups Sulfides Cation* + S Oxides Cation + 0 Halides Cation + CI, F, I, or Br Sulfates Cation + S04 Carbonates Cation + C03 Phosphates Cation + PO4 Silicates Variations involving Si04 Rock forming minerals Silicates Olivine [Femags] Pyroxene Ferromagnesium Amphibole Silicates Mica Group Biotite Muscovite Feldspar Group Plagioclase Alkali K-spar Silicates Quartz Silica Chert *k, Na, Ca Clay minerals - hydrated alumno, silicates Nonsilicates CalcitettiAragonite Dolomite REFRESHER Independent tetrahedral ... Si04 Single chain ... Si03 Double chain ... Si4011 Sheets ... Si205 Framework ... Si02 Framework with holes ... AISi308