Vote for your favorite mineral in #MinCup26! - Sphalerite vs. Anorthite
Both zinc ore Sphalerite and calcium plagioclase feldspar Anorthite have perfect cleavage that will split cleanly if you hit them with a hammer, but only one can claim a larger split of your votes!
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Alunite from
The Geysers, West Mayacmas Mining District, Sonoma County, California, USA


Locality type:Geothermal Field
Classification
Species:Alunite
Formula:KAl3(SO4)2(OH)6
Comments:In 3-9 cm thick veins near Lemonade Springs where it appeared hard and porcelaneous with a smooth fracture, and nearby in veins with greater witdth- where it appeared soft and resembled white clay. (Dunning & Cooper 1993)
Abundance at site:Common
Confirmation
Validity:Believed Valid
Data
Mineral Data:Click here to view Alunite data
Locality Data:Click here to view The Geysers, West Mayacmas Mining District, Sonoma County, California, USA
Data Identifiers
Mindat Occurrence Record ID:456
Long-form Identifier:1:3:456:5
GUID (UUID V4):0
Nearest other occurrences of Alunite
25.4km (15.8 miles) ⓘSulphur Bank Mine (Sulfur Bank Mine; Sulphur Bank deposits), Clear Lake Oaks, Sulphur Creek Mining District (Sulfur Creek Mining District; Wilbur Springs Mining District), Lake County, California, USA
43.3km (26.9 miles) ⓘSulphur Creek deposit, Sulphur Creek Mining District (Sulfur Creek Mining District; Wilbur Springs Mining District), Coast Ranges, Colusa County, California, USA
53.8km (33.4 miles) ⓘUnnamed Alunite occurrence [1], Hooker Canyon, Glen Ellen, Sonoma Mountains, Sonoma County, California, USA
References
Vonsen, Magnus (1941) Preliminary report on minerals of The Geysers of Sonoma County, California. Mineralogist: 9: 247
Vonsen, Magnus (1946), Minerals at “The Geysers,” Sonoma County, California: California Division Mines Report 42: 290
Pemberton, H. Earl (1983) Minerals of California. Van Nostrand Reinhold Company Inc.
Cooper, Joseph F., Dunning, Gail E. (1993) History and Minerals of The Geysers, Sonoma County, California. The Mineralogical Record, 24 (5) 339-354
 
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