Bismoclite

Bismoclite is a bismuth oxohalide mineral with formula BiOCl. The name was derived from its chemical constituents. It is a secondary bismuth mineral composed of bismuthyl ions (BiO) and chloride anions. It is member of the matlockite group.

It was first described in 1935 from alluvium near bismuth-bearing pegmatites in South Africa. It has been found in association with granite pegmatite and in greisen. Associated minerals include: bismutite, mica, jarosite, alunite, cerussite, atacamite, connellite. Occurrences include the type locality at Jackals Water, SW of Prieska, South Africa; Bygoo, Australia; the Tintic district in the East Tintic Mountains of Utah; and from Dalbeattie, Scotland.