Mineral Species: Vivianite

Chemical Formula: Fe3(PO4)2.8H2O

Chemical Name: Hydrated Iron Phosphate

Mineral Class: Phosphate

Mineral Notes:  Vivianite ocurs as an alteration product of iron ores or iron phosphates under near-surface conditions. It is also found as coatings 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 green crystals.

Description: A fossilised oyster shell containing numerous crystalline clusters of black vivianite. Two of the crystal groups have formed into spiny spherical clusters.

Location: Kerch Peninsula, Crimea, Ukraine.