Min - Table 1.7 GY 111 mineral catalog grouped according to luster streak hardness and cleavage Minerals that display significant variation in

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Table 1.7. GY 111 mineral catalog grouped according to luster, streak, hardness and cleavage. Minerals that display significant variation in properties (especially color) are shaded. Suite indicated the most common rock types in which these minerals occur: I: igneous; S: sedimentary; M: metamorphic; H: hydrothermal; A: all rock types. Use caution when testing for mineral hardness. Some minerals (e.g., kyanite) display distinctly different hardnesses depending upon orientation or surface condition. MINERAL CHARACTERISTICS AND DESCRIPTIONS SUITE* MINERAL NAME Greenish yellow color, may tarnish. H=3.5-4. S.G.=4.2. Streak greenish black. Usually massive, no visible crystal form or cleavage. May be associated with other sulfide minerals, especially pyrite. I, H Chalcopyrite Lead gray color. H=2.5. S.G.=7.6. Streak lead gray. Three directions of perfect cleavage at 90 ° . Cubic crystal form with a step-like appearance to broken surfaces. I, S, H Galena Gray to black color. H=1. S.G.=2. Streak black. One direction of cleavage. Marks paper and fingers. Greasy feel. M Graphite Gray to black color, occasionally with reddish highlights. H=6. S.G.=5.2. Streak black. No cleavage . Usually occurs in massive form. Rare crystals are octahedral. Strongly magnetic, a diagnostic property. A Magnetite Grey, black, greenish- black streak Pyrite brass yellow color. H=6-6.5 S.G.=5. Streak greenish black. No cleavage. Cubic crystal form is common. Striations common on crystal faces. A Pyrite Copper streak Pure specimens and fresh surfaces are metallic copper in color. Most specimens are dark brown to green in color. H=2.5 - 3. S.G.=8.9. V, H Copper METALLIC LUSTER Pale yellow streak Dark brown to yellow brown color. H=3.5-4. S.G.=4. Resinous luster. Streak pale yellow. Six directions of cleavage, but seldom well developed. Powdered mineral (when streaked) smells like sulfur. I, S, H
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This note was uploaded on 02/04/2012 for the course GLY 111 taught by Professor Haywick during the Fall '11 term at S. Alabama.

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