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 1 Uses of caledonite 2 Associated minerals 3 Alternative names 4 Notes for identification 5 References

[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.

[edit] References

• Webmineral Listing
• MinDat Listing
• Mineral Galleries