Vivianite, Fe3(PO4)2.8H2O Hydrated Iron Phosphate, ocurs as an alteration product of iron ores or Iron phosphates under near-surface conditions. It is also found as cotings and concretions in newly laid deposits containing organic material such as bones, shells and wood. The mineral is popular amongst collectors because it forms stunning black or almost black crystals.

Description: An interesting pock-marked matrix whose cavity is entirely filled by large, black vivianite crystals. These are mostly fused together, but at the front are a numver of large fan-like sprays. These are completely undamaged and have a very bright luster. A very attractive and rare specimen.

Location: Morococala Mine, Ururo, Bolivia.