Catalog Search Guide
You can search our catalog using different mineral attributes. For example, you can search by color such as green, yellow or purple, or by chemical elements such as uranium, calcium or iron, or by mineral groups such as phosphate, silicate or carbonate. You can also filter by crystal habit like crystal, geode or crystal on matrix, by specimen size such as thumbnail, small, medium or cabinet, and by features such as radioactive or fluorescent minerals.
Vivianite
Vivianite is a hydrated iron phosphate, Fe3(PO4)2·8H2O, prized by collectors for its striking prismatic to bladed crystals in shades of deep blue, bluish-green and even purplish-black. Fresh crystals are pale and almost colorless, but light-induced oxidation gradually darkens them through blue, green and purple tones — a fascinating internal transformation, unrelated to any exposure to air or moisture, that gives every specimen its own unique character.
The finest gem-grade material comes from Bolivia, especially the Siglo XX Mine and San José/San Firmín vein at Llallagua, producing transparent bottle-green prisms on botryoidal goethite matrix. Brazil's Cigana Mine in Minas Gerais yields wedge-shaped crystals sparkling with muscovite and pyrite, while the Kerch Peninsula on the Black Sea is legendary for dark, spear-like blue-green blades, and Cameroon has produced the world's largest known vivianite crystals, exceeding a meter in length. The species' type locality, Wheal Kind in Cornwall, England, anchors its history to 1817, while Blackbird Mine in Idaho is famous for rare purple-zoned crystals.
Vivianite forms in bog iron deposits, phosphate-rich pegmatites, glauconitic clays and hydrothermal veins, often replacing fossil bone, shell and peat. Collectors seek it for its rich color saturation, dramatic crystal habit and evocative genesis stories — but every piece demands careful, low-light storage to preserve its color against the mineral's natural tendency to darken over time.
