Mineral Identification

Directions: Identify the following minerals using the chart on the back.

Mineral: Mineral: Color: Green or dull green. Color: Pink Density: 3.2 ‐ 3.6, Average = 3.4 Density: 2.56 Hardness: 5‐6.5 Hardness: 6 Luster: Glassy nonmetallic Luster: Glassy Streak: greenish gray Streak: White

Mineral: Mineral: Color: Black or dark green. Color: Reddish brown or reddish black Density: 3.0 ‐ 3.5, Average = 3.3 Density: 5.3 Hardness: 5‐6 Hardness: 6.5 Luster: Glassy Pearl Luster: Metallic Streak: White Streak: Reddish brown

Mineral: Mineral: Color: Green, Yellow‐green Color: Light gray Density: 3.2 ‐ 3.3, Average = 3.27 Density: 7.2 ‐ 7.6, Average = 7.4 Hardness: 6‐7 Hardness: 2.5 Luster: Glassy Luster: Metallic Streak: White Streak: Grayish black

Mineral: Mineral: Iron black, Dark gray, Black, Colorless, White, Pink, Yellow, Color: Color: Steel gray Brown Density: 2.09 ‐ 2.23, Average = 2.16 Density: 2.71 Hardness: 1.5‐2 Hardness: 3 Luster: Metallic Luster: Glassy Streak: Gray Streak: White

Mineral: Mineral: Color: Yellow White, Clear, Light blue, Dark Color: Density: 2.05 ‐ 2.09, Average = 2.06 blue, Pink Hardness: 1.5‐2.5 Density: 2.17 Luster: Resinous (like syrup) Hardness: 2.5 Luster: Glassy Streak: white Streak: White Mineral Identification ‐ Diagnostic Physical Properties 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, H=6, streak is green 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); white streak; density near 2.7 g/ml Corundum H=9, often shows hexagonal crystal form Dolomite Reacts to HCL in its powdered form, similar properties to calcite Feldspar H=6‐7; pink/orange color with a white streak test. Hardness ranges from 6‐7 and density ranges from 2.1‐2.5 g/ml 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); H=2.5; Streak is grayish black. Garnet Typically reddish brown color, no cleavage, commonly found in twelve‐sided crystals (dodecahedrons) Graphite "Pencil lead", soft metallic mineral, gray streak; Slightly harder than talc (1.5‐2.0) Gypsum H=2, can be scratched with a fingernail. Typical density ranges from 2.3 to 2.5 g/ml. Halite "Salt", H=2.5, cannot be scratched with a fingernail, 3 directions of cleavage (cubic), salty taste; luster is glassy with a density ranging from 2.1 to 2.5 g/ml Hematite Reddish brown streak, "rust" Hornblende Black to dk. green color, 2 directions of cleavage at 120 or 60 degrees, similar properties to Augite; streak is white; pearl like luster; H=5 Magnetite Magnetic, metallic mineral with a hardness of 5‐6, denisty ranges from 5 to 5.5 g/ml 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; luster is glassy; streak is white Orthoclase H=6, salmon pink color is typical, perthitic intergrowths are common, 2 directions of cleavage at 90 degrees, similar properties to plagioclase; streak is white 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; luster is nonmatallic (glassy) with a density around 2.6 g/ml Sulfur Yellow color, "rotten egg" smell if burned; H=1.5‐2.5; streak is white Talc H=1, very soft, easily scratched by fingernail