Mineralpedia Details for Johannite
Johannite
Named to honor Austrian Archduke Johann Baptist Josef Fabian Sebastian, the founder of the Landesmuseum in Graz, Austria. Johannite is an uncommon mineral that forms in oxidized, sulfide-bearing uraninite deposits, and usually forms post-mine. It can be found in localities in the Czech Republic, Germany, England, France, Tajikistan, Gabon, the United States, and Canada, among a couple others. Johannite is strongly radioactive. It will decompose in water and leaves a bitter or sour taste.
Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/johannite.pdf
- Formula
- Cu(UO2)2(SO4)2(OH)2ยท8H2O
- Crystal System
- Triclinic
- Crystal Habit
- Druse, Reniform, Massive
- Cleavage
- Good, None, None
- Luster
- Vitreous (Glassy)
- Color
- yellow, greenish yellow
- Streak
- light green
- Class
- Triclinic - Pinacoidal
- Fracture
- Irregular
- Hardness
- 2
- WebMineral
- View Johannite
- Mindat
- View Johannite
Johannite from Happy Jack mine, White Canyon, San Juan Co., Utah, United States
Light green crystal aggregated of Johannite to 1mm with blazing orange-yellow Zippeite.
Johannite from Blue Lizard mine, Red Canyon, San Juan Co., Utah, United States
Bright green earthy to crystalline Johannite intermixed with yellow Andersonite.
