Mineralpedia Details for Jarosite
Jarosite
Named after the Barranco del Jaroso in Spain, from which the first studied specimens came from. Jarosite is a widespread and relatively common mineral that occurs “as a secondary mineral in oxidized portions of sulfide-bearing rocks, typically altering from pyrite” as well as less commonly in low-temperature hydrothermal deposits, including those around hot springs, as a primary mineral. Localities for well studies Jarosite specimens include in Spain, the Czech Republic, Germany, Greece, the United States, Mexico, Chile, and Russia. Jarosite is strongly pyroelectric, generates a charge in response to heat.
Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/jarosite.pdf
- Formula
- KFe3+3(SO4)2(OH)6
- Crystal System
- Trigonal
- Crystal Habit
- Crystalline - Fine, Fibrous, Massive
- Cleavage
- Distinct, None, None
- Luster
- Vitreous (Glassy)
- Color
- brown, yellow, yellow brown, light yellow
- Streak
- yellow
- Class
- Trigonal - Pyramidal
- Fracture
- Uneven
- Hardness
- 2.5-3.5
- WebMineral
- View Jarosite
- Mindat
- View Jarosite
Jarosite from Colorado #1 mine, Tintic dist., Juab Co., Utah, United States
2-3mm chocolate brown and highly lustrous, tabular - trigonal-rhomb. habit.
Jarosite from San Rafael mine, Nye Co., Nevada, United States
Lustrous brown micro crystals in limonitic matrix.
