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Chemical Formula | Zn2(AsO4)(OH) | |||||||||||
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Composition | Basic Zinc Arsenate. May contain appreciable amounts of copper and cobalt. | |||||||||||
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Variable Formula | (Zn,Cu,Co)2(AsO4)(OH) | |||||||||||
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Color | Light to dark yellow, greenish yellow, green, greenish blue, pink to purple; rarely colorless, white, or red | |||||||||||
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Streak | White | |||||||||||
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Hardness | 3½ | |||||||||||
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Crystal Forms and Aggregates |
(Orthorhombic) Usually as clusters of short, stubby crystals, but sometimes occurs in elongated prisms, usually in groupings. Also occurs acicular, radiating, and globular. | |||||||||||
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Transparency | Transparent to translucent | |||||||||||
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Specific Gravity | 4.3 - 4.5 | |||||||||||
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Luster | Vitreous | |||||||||||
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Cleavage | 1,1 ; 3,1 | |||||||||||
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Fracture | Uneven | |||||||||||
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Tenacity | Brittle | |||||||||||
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Other ID Marks | Usually fluorescent yellow or yellow green in shortwave ultraviolet light | |||||||||||
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Other Names |  Adamine |
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Varieties | Cobalt Adamite - synonym of
Cobaltoadamite (see below) Cobaltoadamite
- Adamite containing some cobalt in its structure, which replaces some zinc. The presence of
cobalt gives it a purple color. Formula = (Zn,Co)2(AsO4)(OH) Copper
Adamite - synonym of Cuproadamite (see
below) Cuproadamite
- Adamite containing some copper in its structure, which replaces some zinc. The presence of
copper gives it a deep green, greenish-blue, or blue
color. Formula = (Zn,Cu)2(AsO4)(OH).
Cuproadamite is the intermediary mineral in a series with
Olivenite Cu2(AsO4)(OH). |
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Polymorphs | Paradamite | |||||||||||
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In Group | Phosphates ; Arsenates | |||||||||||
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All About | Adamite crystals are usually embedded in rusting, crumbly, brown Limonite matrix that stain the hands. Since the Limonite
crumbles when scrubbed, care must be exercised when
washing such specimens. When copper is present in Adamite, the variety Cuproadamite is formed. The copper in the structure "kills" the usual fluorescence of Adamite, hence Cuproadamite is not fluorescent. |
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Uses | Adamite is a fine specimen mineral, and is much collected by mineral collectors. Adamite is a minor ore of zinc. | |||||||||||
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Striking Features | Association with Limonite, and usually strong fluorescence. | |||||||||||
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Popularity (1-4) | 2 | |||||||||||
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Prevalence (1-3) | 3 | |||||||||||
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Demand (1-3) | 2 | |||||||||||
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Distinguishing Similar Minerals |
Olivenite - usually has a
greener color and usually occurs in tall, thin crystals Smithsonite - usually occurs finely globular, and doesn't fluoresce Paradamite - different crystal form |
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Commonly Occurs With |
Limonite, Aurichalcite, Austinite, Mimetite, Wulfenite, Hemimorphite, Legrandite, Paradamite | |||||||||||
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Noteworthy Localities |
Adamite does not occur in many places. It is found in Laurium, Greece; Chañarcillo, Atacama Desert, Chile; in numerous places in Cumbria and Cornwall, England; and in Cap Garonne, Le Pradet, France (the only place it occurs without Limonite). In the U.S., small colorless crystals were found at the Chloride Cliff, Death Valley, Inyo Co., California. Small crystals also occur in San Bernardino Co., California, and in Gold Hill, Tooele Co., Utah. The most magnificent occurrence for this mineral is wothout doubt the Ojuela Mine in Mapimi, Durango, Mexico, where large, beautiful, and highly fluorescent examples occur in all different colors. | |||||||||||
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Picture Icon Links |
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Picture Links | 1. Adamite
crystals on Limonite 2. Adamite crystals in Limonite pocket 3. Cuproadamite crystals on Limonite 4. Green Adamite on Limonite |
