Search Mineralpedia – A Mineral Photo Database and Identification Guide

Named for the Latin word auripigmentum, meaning “golden paint,” in reference to Orpiment’s golden-yellow color. Orpiment is somewhat common in small amounts, however excellent crystal specimens are rare and can be found in localities in the United States, Slovakia, Bosnia-Herzegovina, Macedonia, Iran, Turkey, Russia, Georgia, China, and Peru. It occurs “in low-temperature hydrothermal veins, hot springs, and fumaroles,” and is also commonly found as a product of the alteration of arsenic minerals, in particular, realgar.

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

Named as an orthorhombic (ortho) mineral and its relationship to pinakiolite. Orthopinakiolite is a rare mineral found only at its type locality at Långban in Sweden where it occurs “in veinlets in granular dolomite in a metamorphosed Fe-Mn orebody.” Orthopinakiolite occurs in association with hausmannite, manganophyllite, dolomite, and calcite.

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

Named as an orthorhombic (ortho) mineral and its relationship to serpierite. Orthoserpierite is an uncommon mineral found as a secondary mineral on hydrothermal copper mine dumps, as well as a precipitate from waters running through oxidized hydrothermal copper deposits. It can be found in localities in France, Ireland, Germany, and the USA among only a few others. Orthoserpierite will fluoresce a lilac-lavender color under long-wave and short-wave ultraviolet light.

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

Named after the first noted occurrence and type locality at the Osarizawa mine on Honshu in Japan. Osarizawaite has many localities including in, additionally, Australia, New Zealand, Argentina, Chile, Mexico, the United States, England, France, and Germany, among others. It occurs as a hydrothermal mineral in oxidized lead-zinc-copper deposits. Osarizawaite occurs in association with anglesite, beaverite, hidalgoite, duftite, bindheimite, conichalcite, olivenite, quartz, clays, and goethite.

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

Named for the type locality at the old province of Osumi in Sakkabira in the Osumi Peninsula on Kyushu, Japan. Because most Osumilite found is Osumilite-(Fe), it is safe to refer to it as just Osumilite. It is an uncommon mineral found in other localities including in the United States, Italy, and Germany among a few others. Osumilite forms in cavities in the groundmass of rhyolites and dacites as well as in high-grade contact metamorphosed rocks and xenoliths. Osumilite is found in association with tridymite, cristobalite, quartz, oligoclase, potassic feldspars, fayalite, hypersthenes, biotite, magnetite, and zircon.

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