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Chemical Formula | CuSO4(OH)6 | ||
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Composition | Basic copper sulfate | ||
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Color | Bright green to dark green | ||
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Streak | Pale green | ||
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Hardness | 3½ - 4 | ||
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Crystal Forms and Aggregates |
(Monoclinic) Very rarely occurs in crystals, which are prismatic and tabular, and almost always small. Most commonly acicular, radiating, earthy, grainy, encrusting, as fibrous masses, as dense bundles of acicular crystals, and as cotton-like, radiating masses. Sometimes occurs as tiny twinned crystals that appear orthorhombic with rounded corners. | ||
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Transparency | Transparent to translucent in thin splinters | ||
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Specific Gravity | 4.0 | ||
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Luster | Vitreous to silky | ||
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Cleavage | 1,1 - pinacoidal | ||
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Fracture | Conchoidal, uneven, splintery | ||
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Tenacity | Brittle | ||
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In Group | Sulfates ; Hydrous sulfates | ||
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All About | Brochantite is a secondary copper mineral formed in the oxidation zone of copper deposits. It is a fragile mineral, and care must be taken when handling. | ||
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Uses | Brochantite is an ore of copper in some localities. | ||
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Striking Features | Intense green color, crystal habits, and mode of occurrence | ||
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Popularity (1-4) | 3 | ||
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Prevalence (1-3) | 2 | ||
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Demand (1-3) | 2 | ||
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Distinguishing Similar Minerals |
Malachite - effervesces in hydrochloric acid; otherwise
practically indistinguishable from Brochantite Antlerite - basically indistinguishable from Brochantite without complex tests. |
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Commonly Occurs With |
Malachite, Azurite, Cyanotrichite, Chalcopyrite, Bornite | ||
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Noteworthy Localities |
Brochantite has many European localities,
including numerous deposits in Cornwall, England; the
Leadhills of Scotland; and the island of Sardinia in
Italy. Fine examples have also come from Bou B'ker,
Touissit, Morocco; Ain Barbar, Algeria; Tsumeb, Namibia;
Burra Burra, South Australia; and Chuquicamata, Chile. Excellent specimens have also come from many areas in the southwestern U.S., in Bisbee, Cochise Co., Arizona; Clifton and Morenci, Greenlee Co., Arizona; the Silver Hill mine, Pima Co., Arizona; the Grandview Mine, Concino Co., Arizona; the Tintic District, Juab Co., Utah; the Cerro Gordo and Green Monster mines, Inyo Co., California; the Monarch Mine, Chaffee Co., Colorado; and near Paoli, Garvin Co., Oklahoma. Also occurs in Idaho in the Alder Creek district, Custer Co. and the Seven Devils district, Adams Co. |
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Picture Icon Links |
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Picture Links | 1. Green mass of tiny radiating Brochantite crystals |
