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Arsenate minerals usually refer to the naturally occurring orthoarsenates, possessing the (AsO 4) 3− anion group and, more rarely, other arsenates with anions like AsO 3 (OH) 2− (also written HAsO 4 2−) (example: pharmacolite Ca(AsO 3 OH). 2H 2 O) or (very rarely) [AsO 2 (OH) 2] − (example: andyrobertsite). Arsenite minerals are much ...
Transition metal arsenate compounds are often brightly coloured and have been used to make pigments. Copper arsenate was a minor compound used in the Egyptian blue pigment used by the ancient Egyptians and Romans. [10] Cobalt violet pigment was made from cobalt arsenate before its toxicity led to its replacement by cobalt phosphate. [11] [12 ...
Arsenate minerals are those minerals containing the arsenate (AsO 4 3−) anion group. Both the Dana [1] and the Strunz [2] mineral classifications place the arsenates in with the phosphate minerals .
A colourless salt, it was originally used as a pesticide and as a germicide. It is highly soluble in water, in contrast to lead arsenate, which makes it more toxic. Two minerals are hydrates of calcium arsenate: rauenthalite Ca 3 (AsO 4) 2 ·10H 2 O and phaunouxite Ca 3 (AsO 4) 2 ·11H 2 O. [4] A related mineral is ferrarisite (Ca 5 H 2 (AsO 4 ...
Synthetic arsenates include Scheele's Green (cupric hydrogen arsenate, acidic copper arsenate), calcium arsenate, and lead hydrogen arsenate. These three have been used as agricultural insecticides and poisons. The protonation steps between the arsenate and arsenic acid are similar to those between phosphate and phosphoric acid.
Mimetite is a lead chloride arsenate mineral with the composition Pb 5 (AsO 4) 3 Cl. It is a secondary mineral, formed by oxidation of primary lead minerals in arsenic-bearing lead deposits. [ 2 ] It typically forms short hexagonal crystals that are yellow to brown to orange in color, very brittle, moderately hard ( Mohs hardness 3.5–4), and ...
The enzymes involved are known as arsenate reductases. In 2008, bacteria were discovered that employ a version of photosynthesis with arsenites as electron donors, producing arsenates (just like ordinary photosynthesis uses water as electron donor, producing molecular oxygen). The researchers conjectured that historically these ...
The rare mineral adelite, is a calcium, magnesium, arsenate with chemical formula CaMgAsO 4 OH. It forms a solid solution series with the vanadium-bearing mineral gottlobite. Various transition metals substitute for magnesium and lead replaces calcium leading to a variety of similar minerals in the adelite–duftite group.