Caledonite, whose name derives from Caledonia, the historical name of its place of discovery (Scotland

Scotland

Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

), is a richly colored blue-green sulfate

Sulfate

In inorganic chemistry, a sulfate is a salt of sulfuric acid.-Chemical properties:...

-carbonate

Carbonate

In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....

 mineral

Mineral

A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...

 of lead

Lead

Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...

 and copper

Copper

Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

 with an orthorhombic crystal

Crystal

A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...

 structure. It is an uncommon mineral found in the oxidized zones of copper-lead deposits.

Collectible properties

Caledonite's primary use is a collector's mineral. Although it contains copper and lead, it is a secondary mineral and is not prevalent enough in any known deposits to be used as an ore

Ore

An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....

. Caledonite, when developed into full crystals, can have a deep blue-green color reminiscent of secondary copper minerals. Its high lustre, on the other hand, is more like secondary lead minerals. Localities in which caledonite occurs as well developed crystals are quite rare and include the Mammoth-St. Anthony Mine at Tiger, Arizona

Tiger, Arizona

Tiger is a ghost town in Pinal County in the U.S. state of Arizona. The town was settled as Schultz around 1881 in what was then the Arizona Territory, then later reestablished as Tiger after World War I.-History:...

, a few mines in California, such as the Reward Mine. A few other mines in Arizona and Chile have been known to produce samples.

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

Linarite

Linarite is a somewhat rare, crystalline mineral that is known among mineral collectors for its unusually intense, pure blue color. It is formed by the oxidation of galena and chalcopyrite and other copper sulfides. It is a combined copper lead sulfate hydroxide with formula PbCuSO42.Linarite...

, malachite

Malachite

Malachite is a copper carbonate mineral, with the formula Cu2CO32. This green-colored mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagmitic masses. Individual crystals are rare but do occur as slender to acicular prisms...

, cerussite

Cerussite

Cerussite is a mineral consisting of lead carbonate , and an important ore of lead. The name is from the Latin cerussa, white lead. Cerussa nativa was mentioned by Conrad Gessner in 1565, and in 1832 F. S. Beudant applied the name cruse to the mineral, whilst the present form, cerussite, is due to...

, brochantite

Brochantite

Brochantite is a sulfate mineral, one of a number of cupric sulfates. Its chemical formula is CuSO4·3Cu2. Formed in arid climates or in rapidly oxidizing copper sulfide deposits, it is named for its discoverer, the French geologist and mineralogist, A. J. M...

, anglesite

Anglesite

Anglesite is a lead sulfate mineral with the chemical formula PbSO4. It occurs as an oxidation product of primary lead sulfide ore, galena. Anglesite occurs as prismatic orthorhombic crystals and earthy masses, and is isomorphous with barite and celestine. It contains 74% of lead by mass and...

, leadhillite

Leadhillite

Leadhillite is a lead sulfate carbonate hydroxide mineral, often associated with anglesite. It has the formula Pb4SO422.Leadhillite crystallizes in the monoclinic system, but forms pseudo-hexagonal forms due to crystal twinning. It forms transparent to translucent variably colored adamantine crystals...

, and azurite

Azurite

Azurite is a soft, deep blue copper mineral produced by weathering of copper ore deposits. It is also known as Chessylite after the type locality at Chessy-les-Mines near Lyon, France...

.