Vivianite Crystal Cluster

Vivianite is a very soft hydrated iron phosphate mineral named after John Henry Vivian, a mineralogist who "discovered" it in his home county of Cornwall, England in the early 1800s. Usually found as deep blue to deep green prismatic to flattened crystals, with most crystals rather small to microscopic, larger vivianite crystals are rather rare. Vivianite can form on human remains, as well as on fossils, thanks to their phosphate content.