1.9" Purple Chromium-Bearing Iowaite with Serpentine - Siberia

Iowaite is a hydrous magnesium hydroxide-ferric oxychloride that commonly forms in compact masses, but it can also be found as isolated crystals like those collected from the Palabora mine in South Africa. It owes its name to the state of Iowa, where it was first discovered at a depth of approximately 1500 feet in a Precambrian serpentine. It typically occurs as blue-green crystals, though once introduced to the atmosphere, the color often changes due to chemical alteration. Impurities can result in iowaite bearing a variety of colors: for example, chromium-bearing iowaite specimens like those found in Siberia, Russia will typically display a vibrant purple coloration.

Chemical formula - Mg6Fe3+2(OH)16Cl2 · 4H2O