Description
Vivianite is a hydrated iron phosphate mineral found in a variety of geological environments. Small amounts of manganese Mn2+, magnesium Mg, and calcium Ca can replace iron Fe2+ in the structure. Pure vivianite is colorless, but the mineral oxidizes very readily, changing its color, and is typically found as deep blue to deep bluish-green prismatic to flattened crystals. Vivianite crystals are often found in fossil shells, such as those of bivalves and gastropods, or attached to fossil bone. It was named by Abraham Gottlob Werner in 1817, the year of his death, after John Henry Vivian (1785–1855), a Welsh-Cornish politician, mine owner, and mineralogist who lived in Truro, Cornwall, England, or after Jeffrey G. Vivian, an English mineralogist. Vivianite was discovered at Wheal Kind, in St. Agnes, Cornwall.
