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Adamite Mineral Facts:

Chemical Formula: Zn₂(AsO₄)(OH)
A rare constituent of oxidized zinc deposits. Variable series substitution of copper for zinc, resulting at full substitution in the green copper end member Olivenite. Some specimens may contain appreciable cobalt  as well.

Colors: Various shades, white to gray, yellow green, pale yellows, brownish yellow, etc.
Some cobalt bearing varieties can be shades of pink or purple. Copper bearing varieties are more intensely green colored.

Hardness: 3.5

Density: 4.32 to 4.48

Cleavage: Poor cleavage, and is brittle.

Crystallography: Orthorhombic
Often in radiating crystal clusters, sometimes in a single crystal  prismatic habit with termination. Also can be found reniform, fibrous, or granular.

Luster:. Normally found with a vitreous luster, sometimes waxy to greasy, occasionally earthy. Transparent to opaque.

Composition, Structure and Associated Minerals:
Adamite crystals are usually closely associated with a crumbly, brown Limonite matrix that fall apart or stain the hands. It is also associated with other secondary zinc minerals.

Identification and Diagnostics
Fuses easily to a mass that appears crystalline on cooling. It gives the usual reactions for H2O, Zn, and As. It is soluble in acids. Characterized chiefly by the elements of its chemical nature. The mineral is often fluorescent green or yellow-green in shortwave ultraviolet light.

Occurrence, Localities and Origins:
Adamite is associated with other zinc compounds in some arsenic bearing zinc ores. It occurs in small amounts at many of the localities for known for secondary zinc minerals, where it is a decomposition product of other zinc compounds. Its origin is secondary in all cases. Better quality specimens occur in the mines of Durango, Mexico, and Copiapó Province, Atacama Region, Chile. Also Laurion, Greece; Cap Garonne, France and Tsumeb, Namibia. In the US, it is found at Gold Hill, Tooele Co., Utah.

It forms some very attractive mineral specimens and so is valued by many crystal collectors.  It is also a very minor ore of zinc at some metal mines.

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