Bismoclite

minerals

bismutite

bismuthinite

jarosite

Formula: BiOCl
Oxyhalide, matlockite group, forms a series with daubréeite
Specific gravity: 7.36
Hardness: 2 to 2½
Streak: White
Colour: Cream-white, greyish, yellowish brown; colourless in thin section
Solubility: Totally soluble in acids. Re-precipitates upon considerable dilution.
Environments

Igneous environments
Metamorphic environments

Bismoclite is formed by the oxidation of bismuth or bismuthinite, usually under arid conditions (Dana).

At Bygoo, New South Wales, Australia, bismoclite has been found in greisen, associated with bismuthinite (HOM, AM 28.536-540).

At the type locality, Jakkalswater, Steinkopf, Namakwa District, Northern Cape, South Africa, bismoclite has been found in an alluvial specimen, found near bismuth-bearing granite pegmatites, associated with mica and bismutite (Mindat, HOM).

Near Dalbeattie, Scotland, UK, bismoclite is associated with atacamite, connellite and uranium minerals (HOM).

At the Tintic District, Utah, USA, bismoclite is associated with bismutite, jarosite, alunite and cerussite (HOM, AM 28.536-540).

Common impurities: Fe,OH

Back to Minerals