Categoria: B

BREITHAUPTITE

BREITHAUPTITE Breithauptite – NiSb – is a very rare sulfide (Dana), characteristic of hydrothermal Co-Ni-Ag veins. It is part of polymetallic ores, but is never the main ore mineral in the deposit. It is classified in the Nickeline Group. It may contain Fe, Co, As, and S. There is a variety with As. 1. Characteristics […]

BROOKITE

BROOKITE Brookite – TiO2 – is a relatively rare oxide. It is much rarer than rutile and anatase, two other polymorphs of TiO2 (other polymorphs are riesite and akaogiite). It does not form ore, but aesthetic pieces fetch high prices in the collector’s mineral trade. Brookite crystals are typically very small to microscopic, tabular in […]

BOURNONITE

BOURNONITE Bournonite – CuPbSbS3 – is a relatively common sulfosalt that always occurs in small quantities in polymetallic veins and other lead (Pb) deposits, serving as an ore of secondary importance. It is nicknamed “cog-wheel ore” because it forms cross-shaped twins at angles of nearly 90° or twins that resemble a cogwheel. These twins can […]

BRUCITE

BRUCITE Brucite – Mg(OH)2 – is a relatively rare hydroxide. It is an important industrial mineral, being a source of the metal magnesium and of magnesia, in addition to applications in refractories, plastics and many other uses. It is classified in the Brucita Group. Very rarely it forms large crystals, but the literature reports cases […]

BARYTE

BARYTE Baryte – BaSO4 – is a relatively common sulfate, being the main ore mineral of Ba. Baryte crystals can exhibit a characteristic chisel-like shape, so one of the German names is “Meisselspat” (“Meissel” = chisel, “spat” = cleaved crystal). The crystals reach lengths of up to 85 cm. More than 70 different combined forms […]

BOULANGERITE

BOULANGERITE Boulangerite – Pb5Sb4S11 – is a relatively common sulphosalt that integrates Pb-Sb-Cu polymetallic ores. It constitutes Pb ore, as it contains 54.88% Pb (and 26.44% Sb). It has a very typical acicular habit, which is why it is called “feather-ore”. The crystals do not closely resemble fibers or feathers, but resemble an aggregate of […]

BORNITE

BORNITE Bornite – Cu5FeS4 – is a frequent sulfide, being one of the most important copper ore minerals. Bornite crystallizes in the Cubic System at temperatures ~ 200ºC. With lowering the temperature, the structure recrystallizes to orthorhombic, but any crystals already formed remain with the original cubic forms. May contain traces of Ag, Ge, Bi, […]

BISMUTH

BISMUTH Bismuth – Bi – is a relatively rare native element, occurring mainly in the Bi-Co-Ni-Ag-Sn paragenesis. The main ores of Bi are bismuthinite and bismite; native bismuth is not an important ore in this context. Most of the Bi is obtained as a byproduct from Pb, W and Cu ores. Bismuth is currently replacing […]