USGS Arsenic Studies GroupArsenic Bearing Minerals |
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|| Arsenic | Realgar | Orpiment | Arsenopyrite | Löllingite | Enargite ||
Arsenic | |
Chemistry | As, Elemental Arsenic |
Color | tin-white which quickly tarnishes to dark gray or black |
Hardness | 3 - 4 |
Specific Gravity | 5.6 - 5.7 |
Crystal System | hexagonal |
Realgar | |
Chemistry | AsS, Arsenic Sulfide |
Color | orange-red |
Hardness | 1.5-2 |
Specific Gravity | 3.48 |
Crystal System | monoclinic |
Orpiment | |
Chemistry | As2S3, Arsenic Sulfide |
Color | lemon-yellow, orange, orange-brownish |
Hardness | 1.5-2 |
Specific Gravity | 3.49 |
Crystal System | monoclinic |
Environment | a sublimation product in fumaroles, and a byproduct of the decay of realgar. |
Arsenopyrite | |
Chemistry | FeAsS, Iron Arsenic Sulfide |
Color | Silverish, whiteish-grey, metallic |
Hardness | 5.5-6 |
Specific Gravity | 6.07 |
Crystal System | monoclinic |
Environment | in sulfide ore deposits, common in medium to high temperature hydrothermal veins. Frequently in metamorphic deposits |
Löllingite | |
Chemistry | FeAs2, Iron Arsenide |
Color | silver white to gray |
Hardness | 5 - 5.5 |
Specific Gravity | 7.1 - 7.5 |
Crystal System | Orthorhombic |
Enargite | |
Chemistry | Cu3AsS4, Copper Arsenic Sulfide |
Color | gray to black |
Hardness | 3 - 3.5 |
Specific Gravity | 4.4+ |
Crystal System | orthorhombic |
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URL: http://wwwbrr.cr.usgs.gov/usgs/Arsenic/minerals.htm Created/Maintained: R. Blaine McCleskey; rbmccles@usgs.gov Last Updated: 04/04/2008 |