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Minerals. Mineral - definition. Naturally occurring Inorganic Solid Specific atomic composition Definite atomic structure. Mineral Identification. 1. Hardness 2. Streak 3. Cleavage/Fracture 4. Luster 5. Specific Gravity 6. Color. Hardness.
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Mineral - definition • Naturally occurring • Inorganic • Solid • Specific atomic composition • Definite atomic structure
Mineral Identification • 1. Hardness • 2. Streak • 3. Cleavage/Fracture • 4. Luster • 5. Specific Gravity • 6. Color
Hardness • Is measured by how easy it is to scratch. • Geologists order the hardness by… • Scratched by a fingernail. • Scratched by a penny. • Scratched by a nail. • Scratched by a diamond. These are not all of the tools geologists use, but it will work for our experiment.
Mineral Identification • Hardness – the ability to resist scratching; ranges from 1 (softest) to 10 (hardest)
Mineral Systems • If space is not restricted, a mineral will exhibit a crystal pattern with a definite number of sides and specific angles.
Mineral Identification Streak • _________ – the color of the powdered form of a mineral
Mineral Identification • Cleavage (flat surfaces) or Fracture (no flat surfaces) – the way a mineral __________ breaks
Mineral Identification • Fracture: ___________________ • Ex. Quartz or obsidian
cleavage Mica is probably the best example as it splits into thin sheets. It is said to have one perfect cleavage.
Calcite and Galena cleave in three directions. They are said to have three good cleavages. cleavage
Not all minerals show cleavage. Those that don’t break along cleavage surfaces are said to have fracture. Fracture
Luster • Refers to the way light reflects from the surface of the mineral. • There are two types of luster, • Metallic: looks like polished metal. • Nonmetallic: does not look like polished metal. • Nonmetallic can be shiny or dull.
Silicates Non Silicates
QUARTZ (Silica) SiO2 CORUNDUM (Alumina) Al2O3 HEMATITE Fe2O3 CALCITE CaCO3 DOLOMITE CaMg(CO3)2 GYPSUM CaSO4 FLUORITE CaF2 PYRITE FeS2 OLIVINE (Mg,Fe)2SiO4 PYROXENE (Mg,Fe)SiO3 AMPHIBOLE (Ca2Mg5)Si8O22(OH)2 FELDSPARS Albite NaAlSi3O8 Orthoclase KAlSi3O8 Anorthite CaAl2Si2O8 KAOLINITE Al2Si2O5(OH)4 COMMON MINERALS IN THE EARTH