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www.mineralgallery.co.za Minerals A-E |
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Name
Adamite
Chemistry
Zn2AsO4(OH), Zinc Arsenate Hydroxide.
Uses
As mineral specimens
Color
Typically green due to trace amounts copper and or uranium, yellow, rarely white and occasionally purple due to trace amount of cobalt. Yellow green to violet
Hardness
3.5
Specific gravity
4.5
Crystals
Orthorhombic.
Accompanied by:
Limonite,olivenite,calcite, Azurite smithsonite.
Fracture
Conchoidal
Luster
Vitreous
Cleavage
Perfect.
Streak
White.
Similar to:
Adamsite and limonite.
Adamite is a mineral that fluoresces green under long and shortwave UV light. It is also an attractive mineral specimen on it's own.
The adamantine (high luster crystals usually has a lime green color of its own. Adamite is not easy to mistake for any other mineral. Its bright green fluorescence, high luster, "sub" botryoidal crystal habit,high density, typical bright green color and double terminations make both an exquisite specimen for a collection and an easy identification.
Adamite at Tsumeb
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Yellow adamite gets its color from the mineral limonite;
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pink and violet come from the metal cobalt;
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while green is caused by the presence of copper .
Occurs as very small yellow to yellow-green crystals rarely over a few mm in size. Some crystals have brown edges parallel to the c-axis.
Copper-free adamite is very rare at Tsumeb; commonly adamite crystals are zoned with varying copper content and varying color. The more in-tensely green crystals have the most copper. Habits range from equant to prismatic.
Adamite is a secondary mineral It only occurs when existing minerals changes form as a result of a chemical reaction.Its elegant crystals makes it popular with collectors.
Adamite melts quite easily and dissolves in dilute acids and in doing so smells like arsenic.Adamite should be cleaned with distilled water.It occurs in Mexico,Namibia and USA.
Varieties of adamite
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Cobaltoadamite: Cobalt variety (Zn,C0)2(AsO4)(OH)Extremely rare at Tsumeb, this variety is an attractive pink color.
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Cuproadamite : Copper variety. Zn,Cu)2(ASO4)(OH)This variety is supposedly part of a continuous series to olivenite. It forms crystals of bright green to apple-green and olive-green color often associated with bayldonite and schultenite on tennantite. Cuproadamite is much more common than low-Cu adamite. Prismatic crvstals up to 13 mm have been found.
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