Science Fair Project Encyclopedia
Galena (mineral)
| Galena | |
|---|---|
| General | |
| Category | Mineral |
| Chemical formula | lead sulfide (PbS) |
| Identification | |
| Colour | Lead gray, silvery |
| Crystal habit | Cubes, tabular and sometimes skeletal crystals |
| Crystal system | Isometric |
| Cleavage | Cubic |
| Fracture | Flat (when cubic) to even |
| Mohs Scale hardness | 2.5 - 2.75 |
| Luster | Metallic |
| Refractive index | Opaque |
| Pleochroism | None |
| Streak | Lead gray |
| Specific gravity | 7.4 - 7.6 |
| Fusibility | ? |
| Solubility | ? |
| Major varieties | |
| None | |
Galena is a mineral, an ore of lead, lead sulfide (PbS). Galena is one of the most abundant and widely distributed sulfide minerals, and is the main ore of lead. Crystals are usually cubic, sometimes octahedral. It is often associated with the minerals sphalerite and fluorite. Galena deposits sometimes contain significant amounts of silver as an impurity, and these galenas have long been the most important ore of silver in mining.
Galena deposits are found in Germany, France, Romania, Austria, Belgium, Italy, Spain, Scotland, England, Australia, and Mexico. In the United States it occurs in Missouri, Illinois, Iowa, Kansas, Oklahoma, Colorado, Idaho, Utah, Montana, and Wisconsin.
Galena is the official state mineral of Missouri and Wisconsin, USA.
See also
- List of minerals
- PbS, for a description of its use in infra-red sensors.
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