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Mineral Identification - Diagnostic Physical Properties |
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| Apatite | Green color, H=5, may show hexagonal crystal form |
| Augite | Dark or dull green color, 2 cleavages at ~90 degrees, similar properties to Hornblende |
| Biotite | Black color, one perfect direction of cleavage resulting in the mineral pealing into thin, flexible sheets, similar properties to Muscovite |
| Calcite | H=3, reacts with HCl, 3 directions of cleavage (rhombic cleavage) |
| Corundum | H=9, often shows hexagonal crystal form |
| Dolomite | Reacts to HCL in its powdered form, similar properties to calcite |
| Fluorite | H=4, 4 directions of cleavage, often purple in color (can be white, clear, yellow, green) |
| Galena | Gray, metallic mineral, 3 directions of cleavage (cubic) |
| Garnet | Typically reddish brown color, no cleavage, commonly found in twelve-sided crystals (dodecahedrons) |
| Graphite | "Pencil lead", soft metallic mineral, gray streak |
| Gypsum | H=2, can be scratched with a fingernail |
| Halite | "Salt", H=2.5, cannot be scratched with a fingernail, 3 directions of cleavage (cubic), salty taste |
| Hematite | Reddish brown streak, "rust" |
| Hornblende | Black to dk. green color, 2 directions of cleavage at 120 or 60 degrees, similar properties to Augite |
| Magnetite | Magnetic, metallic mineral |
| Muscovite | Clear or translucent color, one perfect direction of cleavage resulting in the mineral pealing into thin, flexible sheets, similar properties to Biotite |
| Olivine | Apple green or yellowish green color, H=7 (often difficult to determine), conchoidal fracture, no cleavage |
| Orthoclase | H=6, salmon pink color is typical, perthitic intergrowths are common, 2 directions of cleavage at 90 degrees, similar properties to plagioclase |
| Plagioclase | H=6, white or gray color, striations may be seen on cleavage surface, 2 directions of cleavage at 90 degrees, similar properties to orthoclase |
| Pyrite | "Fool's Gold", gold metallic color |
| Quartz | H=7, conchoidal fracture, no cleavage, color is typically white or clear but can be pink, red, purple, black |
| Sulfur | Yellow color, "rotten egg" smell if burned |
| Talc | H=1, very soft, easily scratched by fingernail |