Search Mineralpedia – A Mineral Photo Database and Identification Guide

Named for American mineral collector Clarence Sweet Bement. It is an uncommon but widespread mineral that occurs in the United States, England, Sweden, Russia, Japan, and South Africa among several others. Bementite can be found in layers parallel to veins of calcite and intergrown with other manganese minerals. Associated minerals include calcite, willemite, hausmanntie, jacobsite, braunite, alleghanyite, baryte, grossular, johannsenite, rhodochrosite, and inesite.

Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/bementite.pdf

Named after the type locality at the Dallas Gem mine in San Benito County in California, USA. Other localities for Benitoite include additional USA localities, as well as in Japan, Australia, and the Czech Republic. At the type locality it can be found in natrolite veins that cut glaucophane schist in a serpentine body, and at the Japanese locality in a magnesio-riebeckite-quartz-phlogopite-albite dike that cuts serpentinite. Benitoite has a blue fluorescence under short wave ultraviolet light and an intense blue cathodoluminescence.

Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/benitoite.pdf

Named for the type locality at Beraun, which is now called Beroun in Bohemia in the Czech Republic. Beraunite is an uncommon mineral that can be found as well studied material in the Czech Republic, Germany, England, Portugal ,Sweden, Australia, and the United States including here in the Black Hills of South Dakota at the Tip Top, White Elephant, Big Chief, Hesnard, Barker-Ferguson, and White Cap mines, among several other known localities. Beraunite occurs as a component in bog iron ore, as a cement in clay, sand, and bone material, and as an alteration product of triphylite in granite pegmatites. Tabular, elogated, dull green to breenish brown crystals found in radial fibrous coarse aggregates, globular to discoudal masses, and crusts.

Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/beraunite.pdf