Home > Uranium Minerals II – November 29 > MS0819 Johannite, Uranopilite

Johannite, Uranopilite - Sold


The Happy Jack mine was an important producer of uranium during America's uranium boom days (1950s-1960s) (San Juan Record, 2009). On the mine walls grew encrustations of colorful exotic uranium sulfate minerals on sandstone. This specimen features an intergrowth of two uranium minerals, green johannite and yellow uranopilite. This is a fragile mineral specimen that may suffer some loss (fragmentation) in shipment.

Originally called uranvitriol, Haidinger (1830) renamed the mineral johannite after making certain crystallographic measurements. The mineral name honors Austrian Archduke Johann Baptist Josef Fabian Sebastian (1782–1859), founder of the Landesmuseum at Graz, Austria. Mereiter (1982) solved the crystal structure of johannite, establishing the formula Cu(UO2)2(OH)2(SO4)2·8H2O. Johannite forms aggregates of green micro crystals with yellow powdery uranopilite. Uranopilite is a hydrated uranium mineral, named for its uranium content and felt-like texture Frondel (1958) (note: file size 24.6MB). Burns (2001) established the formula (UO2)6SO4O2(OH)6·14H2O for uranopilite by crystal structure solution.

This specimen was part of the personal collection of Ralph Merrill, proprietor of the prolific mail order business Minerals Unlimited, obtained in 1961 from Otto Ray, a mineral collector from Salt Lake City. Merrill's collection card and label also ship with the specimen.

Johannite, Uranopilite Johannite, Uranopilite