Phosphates, Arseniates and Vanadates

Phosphates, Arseniates, Vanadates: This class includes about 250 species, or 16% of the total but many are observable only in small crystals. This group of minerals is characterized by a group of 4 ions (atoms) of oxygen located at the tops of a tetrahedron around the pentavalent elements, phosphorus (P), vanadium (V) and arsenic (As). They may also be considered as salts of phosphoric acid (H3PO4), vanadium (H3VO4), or arsenic (H3aso4). Examples: monazite Cepo4, adamite Zn2aso4(OH), vanadinite Pb5(VO4)3Cl …
Primary phosphorus is generally present as apatite in almost all eruptive rocks, in some metalliferous deposits and in pegmatite veins. Arsenates and vanadates are secondary minerals formed in deposits of complex constitutions rich in arsenic and cobalt sulphide. More representatives of Phosphates, Arseniates and Vanadates are : Adamite, Annabergite, Fluorapatite, Augelite, Autunite, Brazilianite, Cafarsite, Descloizite, Erythrite, Lazulite, Legrandite, Libethenite, Ludlamite, Mimetite, Olivenite, Paravauxite, Vauxite, Plumbogummite, Pyromorphite, Roselite, Torbernite, Turquoise, Vanadinite and Vivianite.