Odontolite (Paperback)

High Quality Content by WIKIPEDIA articles! Odontolite, also called bone turquoise or fossil turquoise, is fossil bone or ivory that has been traditionally thought to have been altered by turquoise or similar phosphate minerals such as vivianite. Vivianite Fe3(PO4)2.8(H2O), hydrated iron phosphate, is a secondary mineral found in a number of geological environments. Usually found as deep blue to deep bluish green prismatic to flattened crystals, most crystals rather small to microscopic, larger ones are rare. It is formed by the alteration of ore deposits near the surface, or of primary phosphates in pegmatites. Vivianite crystals are often found inside fossil shells, such as those of bivalves and gastropods, or attached to fossil bone.