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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Black Hawk claim, Knoxville area, Napa County, California, USAi
Regional Level Types
Black Hawk claimClaim
Knoxville areaArea
Napa CountyCounty
CaliforniaState
USACountry

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Latitude & Longitude (WGS84):
38° 46' 35'' North , 122° 23' 2'' West
Latitude & Longitude (decimal):
38.77639,-122.38389
GRN:
N26W69
Type:
Claim
Köppen climate type:
Csb : Warm-summer Mediterranean climate
Nearest Settlements:
PlacePopulationDistance
Hidden Valley Lake5,579 (2011)15.5km
Guinda254 (2011)17.5km
Middletown1,323 (2011)20.2km
Angwin3,051 (2011)23.0km
Lower Lake1,294 (2011)24.6km
Nearest Clubs:
Local clubs are the best way to get access to collecting localities
ClubLocationDistance
Santa Rosa Mineral And Gem Society, Inc.Santa Rosa, California47km
Mindat Locality ID:
83642
Long-form identifier:
mindat:1:2:83642:6
GUID (UUID V4):
0


A former Cr mine located in sec. 23, T11N, R5W, MDM, 6.9 km (4.3 miles) SW of Knoxville. Operated by T.L. Neil.

Production: 126 tons of ore mined and shipped in 1916-1917. Mined out in 1917.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List


1 valid mineral.

Detailed Mineral List:

ⓘ Chromite
Formula: Fe2+Cr3+2O4

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 4 - Oxides and Hydroxides
ⓘChromite4.BB.05Fe2+Cr3+2O4

List of minerals for each chemical element

OOxygen
Oⓘ ChromiteFe2+Cr23+O4
CrChromium
Crⓘ ChromiteFe2+Cr23+O4
FeIron
Feⓘ ChromiteFe2+Cr23+O4

Other Databases

Link to USGS MRDS:10031652

Other Regions, Features and Areas containing this locality

North AmericaContinent
North America PlateTectonic Plate

This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.

References

Dow, D.H. & T.P. Thayer (1946), Chromite deposits of the northern Coast Ranges of California: California Division Mines Bulletin 134, part 2, chapter 1: 20, 34.
USGS MRDS database (2005), loc. file ID #10031652.
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