ADAMITE VARIETY CUPROADAMITE (miniature)

Adamite is a mineral composed of zinc arsenate hydroxide, with the chemical formula Zn2AsO4OH. It is commonly found in the oxidized or weathered zones above deposits of zinc ore.

While pure adamite is colorless, it often exhibits a yellow hue due to the presence of iron compounds. Additionally, green shades can be observed, which are attributed to copper substitutions within its structure. Olivenite, a copper arsenate, shares an isostructural relationship with adamite, and there is significant substitution between zinc and copper, leading to the formation of an intermediate known as cuproadamite. Recently identified, zincolivenite is another intermediate mineral characterized by the formula CuZn(AsO4)(OH), and the structure can also accommodate substitutions from manganese, cobalt, and nickel. Furthermore, a related zinc phosphate mineral called tarbuttite has been documented.