Description
Uvite is an uncommon form of Tourmaline, and it forms different crystal formations than most of the other Tourmalines. Though it lacks the color diversity as some of the other Tourmaline forms, it does occur in beautiful green and reddish-brown crystals, as well as lustrous submetallic crystals. The name Uvite is derived from the type locality of the Uva Province, in Sri Lanka, where it was first identified.
Uvite is very similar to Dravite Tourmaline, and they sometimes for together in a single crystal. It can sometimes be very difficult to make an exact distinction between Dravite, Uvite, and the newly designated Fluor-uvite.
Magnesite, the mineral magnesium carbonate (MgCO3), a member of the calcite group of carbonate minerals that is a principal source of magnesium. The mineral has formed as an alteration product from magnesium-rich rocks or through the action of magnesium-containing solutions upon calcite. Notable deposits are those at Radenthein, Austria; the Liaotung Peninsula, Liaoning Province, China; and Clark County, Nev., U.S. Iron is usually present, and a complete chemical substitution series exists between magnesite and siderite in which iron replaces magnesium. Magnesite is used as a refractory material, a catalyst and filler in the production of synthetic rubber, and a material in the preparation of magnesium chemicals and fertilizers. For detailed physical properties, see carbonate mineral (table).
