Description
This dolomite with uvite tourmaline is from the Pomba Pit in Serra das Egus, Brumado, Bahia, Brazil. This mine is a commercial producer of magnesite and talc however uvite and other accessory minerals, including emeralds are found there. The mine owners enforce a ban on mineral collecting that includes the miners that work there. Uvite is in the Tourmaline Group of minerals and it is a silicate that contains the elements Na, Mg, Al, Si, O, B and H. Dolomite is a carbonate and includes the elements Ca, Mg, C and O. This specimen consists of a formation of stacked, druse, dolomite crystals that is topped with a complex tabular dolomite crystal. The crystals are translucent and contain reddish (probably hematite) phantoms. The piece is intact on all sides and there are drusy green uvite tourmalines scattered about the piece. It measures 25 x 16 x 13 mm.