Caledonite
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| Caledonite | |
|---|---|
| Category | Mineral |
| Chemical formula | Cu2Pb5CO3(SO4)3(OH)6 |
| Identification | |
| Color | Blue; Green |
| Crystal habit | typically prismatic or tabular; radial aggregates |
| Crystal system | Orthorhombic |
| Cleavage | [001] Perfect; [100] Distinct |
| Fracture | Uneven |
| Mohs Scale hardness | 2.5 - 3 |
| Luster | Vitreous |
| Refractive index | 1.81 - 1.90 |
| Pleochroism | None |
| Streak | Green-White; Blue-Green |
| Specific gravity | 5.6 - 5.8 |
| Diaphaneity | Transparent to translucent |
Caledonite, whose name derives from Caledonia, the historical name of its place of discovery (Scotland), is a richly colored blue-green sulfate mineral with an orthorhombic crystal structure, commonly found in the oxidized zones of copper-lead deposits as a secondary mineral.
Contents |
[edit] Uses of caledonite
Caledonite is a very minor ore mineral of lead and copper, but its rarity makes its industrial use limited. Due to its occasionally striking crystals and vibrant color, however, caledonite has value as a collector's mineral.
[edit] Associated minerals
Given that caledonite is found in oxidized copper/lead deposits, it is frequently found in association with other copper and lead minerals. Frequently associated minerals include:
- linarite, CuPbSO4OH2
- malachite, Cu2(CO3)(OH)2
- cerussite, PbCO3
- brochantite, Cu4(SO4)(OH)6
- anglesite, PbSO4
[edit] Alternative names
Caledonite has one major alterative name: caledonita.
[edit] Notes for identification
Caledonite's blue color is a useful indicator, but insufficient, especially since one of its associates, linarite, is a vivid blue as well. Useful tests for determining if a specimen is caledonite include its density, streak, and crystal habit.
