Minerals Set #10: Sulfides and Other Ores
Learn to identify each of these minerals. This means: learn their physical properties, and the information below. Physical properties may be found in the back of the Perkins text.
|
Mineral |
Formula |
Crystal System |
Occurrences and properties |
|
Pyrite |
FeS2 |
Cubic |
Insol. in HCl; powder sol. in HNO3 |
|
Pyrrhotite (Troilite) |
Fe7S8 FeS |
Monoclininc (psedohexagonal) Hexagonal |
Sol. in HCl. Slightly magnetic Troilite is not magnetic and occurs in meteorites and lunar rocks |
Chalcopyrite |
CuFeS2 |
Tetragonal |
Sol. in HNO3 w/precipitation of sulphur |
Sphalerite |
ZnS |
Cubic |
Sol. in HCl w/ evolution of H2S |
|
Galena |
PbS |
Cubic |
Decomposed by H2SO4 and dilute HNO3 |
|
Cinnabar |
HgS | Hexagonal (Rhombohedral) | A principal ore of mercury. |
| Covelite | CuS | Hexagonal | A secondary mineral of copper ores. |
| Stibnite | Sb2S3 | Orthorhombic | Occurs massively and in prismatic crystals that show perfect cleavage and are striated vertically. A principal ore of antimony. |
| Arsenopyrite | FeAsS | Orthorhombic | Occurs in crystalline rocks and in especially lead and silver veins. A principal ore of arsenic. |
| Molybdenite | MoS2 | Hexagonal | A principal ore of molybdenum. Occurs in foliated masses or scales found in dykes and in qtz. veins. |