Caledonite

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Caledonite
Caledonit auf Cerussit - Mineralogisches Museum Bonn (7354).jpg
Caledonite (green) on cerussite
General
Category Sulfate minerals
Formula
(repeating unit)
Cu2Pb5(OH)6CO3(SO4)3
IMA symbol Cdo [1]
Strunz classification 7.BC.50
Crystal system Orthorhombic
Crystal class Pyramidal (mm2)
(same H-M symbol)
Space group Pmn21
Unit cell a = 20.089(7) Å,
b = 7.146(3) Å,
c = 6.56 Å; Z = 2
Identification
ColorBlue; green
Crystal habit Typically striated prismatic or tabular crystals; radial aggregates
Cleavage [001] perfect; [100] distinct
Fracture Uneven
Tenacity Brittle
Mohs scale hardness2.5–3
Luster Vitreous
Streak Green-white; blue-green
Diaphaneity Transparent to translucent
Specific gravity 5.6–5.8
Optical propertiesBiaxial (−)
Refractive index nα = 1.818(3) nβ = 1.866(3) nγ = 1.909(3)
Birefringence δ = 0.091
Pleochroism Weak
2V angle Measured: 85°
References [2] [3] [4] [5]

Caledonite, whose name derives from Caledonia, the historical name of its place of discovery (Scotland), is a richly colored blue-green sulfate-carbonate mineral of lead and copper with an orthorhombic crystal structure. It is an uncommon mineral found in the oxidized zones of copper-lead deposits.

Contents

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. 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, 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, malachite, cerussite, brochantite, anglesite, leadhillite, and azurite. [3]

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.

Related Research Articles

<span class="mw-page-title-main">Turquoise</span> Opaque, blue-to-green mineral

Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium, with the chemical formula CuAl6(PO4)4(OH)8·4H2O. It is rare and valuable in finer grades and has been prized as a gemstone for millennia due to its hue.

<span class="mw-page-title-main">Azurite</span> Copper carbonate mineral

Azurite is a soft, deep-blue copper mineral produced by weathering of copper ore deposits. During the early 19th century, it was also known as chessylite, after the type locality at Chessy-les-Mines near Lyon, France. The mineral, a basic carbonate with the chemical formula Cu3(CO3)2(OH)2, has been known since ancient times, and was mentioned in Pliny the Elder's Natural History under the Greek name kuanos (κυανός: "deep blue," root of English cyan) and the Latin name caeruleum. Copper (Cu2+) gives it its blue color.

<span class="mw-page-title-main">Chalcanthite</span> Sulfate mineral

Chalcanthite (from Ancient Greek χάλκανθον (khálkanthon), from χαλκός (khalkós) 'copper', and ἄνθος (ánthos) 'flower, bloom') is a richly colored blue-green water-soluble sulfate mineral CuSO4·5H2O. It is commonly found in the late-stage oxidation zones of copper deposits. Due to its ready solubility, chalcanthite is more common in arid regions.

<span class="mw-page-title-main">Aurichalcite</span> Basic carbonate of zinc and copper

Aurichalcite is a carbonate mineral, usually found as a secondary mineral in copper and zinc deposits. Its chemical formula is (Zn,Cu)5(CO3)2(OH)6. The zinc to copper ratio is about 5:4. Copper (Cu2+) gives aurichalcite its green-blue colors.

<span class="mw-page-title-main">Cuprite</span>

Cuprite is an oxide mineral composed of copper(I) oxide Cu2O, and is a minor ore of copper.

<span class="mw-page-title-main">Dioptase</span>

Dioptase is an intense emerald-green to bluish-green copper cyclosilicate mineral. It is transparent to translucent. Its luster is vitreous to sub-adamantine. Its formula is Cu6Si6O18·6H2O (also reported as CuSiO2(OH)2). It has a hardness of 5, the same as tooth enamel. Its specific gravity is 3.28–3.35, and it has two perfect and one very good cleavage directions. Additionally, dioptase is very fragile, and specimens must be handled with great care. It is a trigonal mineral, forming 6-sided crystals that are terminated by rhombohedra.

<span class="mw-page-title-main">Atacamite</span> Halide evaporite mineral

Atacamite is a copper halide mineral: a copper(II) chloride hydroxide with formula Cu2Cl(OH)3. It was first described for deposits in the Atacama Desert of Chile in 1802 by Dmitri de Gallitzin. The Atacama Desert is also the namesake of the mineral.

<span class="mw-page-title-main">Adamite</span> Zinc arsenate hydroxide mineral

Adamite is a zinc arsenate hydroxide mineral, Zn2AsO4OH. It is a mineral that typically occurs in the oxidized or weathered zone above zinc ore occurrences. Pure adamite is colorless, but usually it possess yellow color due to Fe compounds admixture. Tints of green also occur and are connected with copper substitutions in the mineral structure. Olivenite is a copper arsenate that is isostructural with adamite and there is considerable substitution between zinc and copper resulting in an intermediate called cuproadamite. Zincolivenite is a recently discovered mineral being an intermediate mineral with formula CuZn(AsO4)(OH). Manganese, cobalt, and nickel also substitute in the structure. An analogous zinc phosphate, tarbuttite, is known.

<span class="mw-page-title-main">Brochantite</span> Copper sulfate mineral

Brochantite is a sulfate mineral, one of a number of cupric sulfates. Its chemical formula is Cu4SO4(OH)6. Formed in arid climates or in rapidly oxidizing copper sulfide deposits, it was named by Armand Lévy for his fellow Frenchman, geologist and mineralogist A. J. M. Brochant de Villiers.

<span class="mw-page-title-main">Linarite</span> Copper lead sulfate hydroxide mineral

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 PbCuSO4(OH)2. Linarite occurs as monoclinic prismatic to tabular crystals and irregular masses. It is easily confused with azurite, but does not react with dilute hydrochloric acid as azurite does. It has a Mohs hardness of 2.5 and a specific gravity of 5.3 – 5.5.

<span class="mw-page-title-main">Crocoite</span> Lead chromate mineral

Crocoite is a mineral consisting of lead chromate, PbCrO4, and crystallizing in the monoclinic crystal system. It is identical in composition with the artificial product chrome yellow used as a paint pigment.

<span class="mw-page-title-main">Ajoite</span>

Ajoite is a hydrated sodium potassium copper aluminium silicate hydroxide mineral. Ajoite has the chemical formula (Na,K)Cu7AlSi9O24(OH)6·3H2O, and minor Mn, Fe and Ca are usually also present in the structure. Ajoite is used as a minor ore of copper.

<span class="mw-page-title-main">Chalcophyllite</span>

Chalcophyllite is a rare secondary copper arsenate mineral occurring in the oxidized zones of some arsenic-bearing copper deposits. It was first described from material collected in Germany. At one time chalcophyllite from Wheal Tamar in Cornwall, England, was called tamarite, but this name is now discredited. At Wheal Gorland a specimen exhibiting partial replacement of liriconite, Cu
2
Al(AsO
4
)(OH)
4
•(4H
2
O)
, by chalcophyllite has been found. The mineral is named from the Greek, chalco "copper" and fyllon, "leaf", in allusion to its composition and platy structure. It is a classic Cornish mineral that can be confused with tabular spangolite.

<span class="mw-page-title-main">Ashburtonite</span>

Ashburtonite is a rare lead copper silicate-bicarbonate mineral with formula: HPb4Cu2+4Si4O12(HCO3)4(OH)4Cl.

<span class="mw-page-title-main">Campigliaite</span>

Campigliaite is a copper and manganese sulfate mineral with a chemical formula of Cu4Mn(SO4)2(OH)6·4H2O. It has a chemical formula and also a crystal structure similar to niedermayrite, with Cd(II) cation replacing by Mn(II). The formation of campigliaite is related to the oxidation of sulfide minerals to form sulfate solutions with ilvaite associated with the presence of manganese. Campigliaite is a rare secondary mineral formed when metallic sulfide skarn deposits are oxidized. While there are several related associations, there is no abundant source for this mineral due to its rare process of formation. Based on its crystallographic data and chemical formula, campigliaite is placed in the devillite group and considered the manganese analogue of devillite. Campigliaite belongs to the copper oxysalt minerals as well followed by the subgroup M=M-T sheets. The infinite sheet structures that campigliaite has are characterized by strongly bonded polyhedral sheets, which are linked in the third dimension by weaker hydrogen bonds.

<span class="mw-page-title-main">Plumbogummite</span> Alunite supergroup, phosphate mineral

Plumbogummite is a rare secondary lead phosphate mineral, belonging to the alunite supergroup of minerals, crandallite subgroup. Some other members of this subgroup are:

<span class="mw-page-title-main">Plancheite</span>

Plancheite is a hydrated copper silicate mineral with the formula Cu8Si8O22(OH)4•(H2O). It is closely related to shattuckite in structure and appearance, and the two minerals are often confused.

<span class="mw-page-title-main">Langite</span>

Langite is a rare hydrated copper sulfate mineral, with hydroxyl, found almost exclusively in druses of small crystals. It is formed from the oxidation of copper sulfides, and was first described in specimens from Cornwall, United Kingdom. It is dimorphous with wroewolfeite. Langite was discovered in 1864 and named after the physicist and crystallographer Viktor von Lang (1838–1921), who was Professor of Physics at the University of Vienna, Austria.

<span class="mw-page-title-main">Diaboleite</span>

Diaboleite is a blue-colored mineral with formula Pb2CuCl2(OH)4. It was discovered in England in 1923 and named diaboleite, from the Greek word διά and boleite, meaning "distinct from boleite". The mineral has since been found in a number of countries.

<span class="mw-page-title-main">Queitite</span>

Queitite is a lead zinc silicate sulphate that was named after the mineral dealer Clive S. Queit, who collected the first specimens. It got approved by the IMA in 1979, and it is an extremely rare secondary mineral.

References

  1. Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi: 10.1180/mgm.2021.43 . S2CID   235729616.
  2. Mineralienatlas
  3. 1 2 "Handbook of Mineralogy" (PDF). Archived from the original (PDF) on 2016-03-03. Retrieved 2016-12-20.
  4. MinDat Listing
  5. Webmineral Listing