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Helmke occurrence, Irish Town, Magalia Mining District, Butte County, California, USAi
Regional Level Types
Helmke occurrenceOccurrence
Irish TownUnincorporated Community
Magalia Mining DistrictMining District
Butte CountyCounty
CaliforniaState
USACountry

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Latitude & Longitude (WGS84):
39° 48' 10'' North , 121° 37' 14'' West
Latitude & Longitude (decimal):
39.80278,-121.62056
GeoHash:
G#: 9r1d2myeg
GRN:
N27W68
Type:
Occurrence
Köppen climate type:
Csa : Hot-summer Mediterranean climate
Nearest Settlements:
PlacePopulationDistance
Magalia11,310 (2011)3.8km
Paradise26,476 (2017)4.8km
Forest Ranch1,184 (2011)9.9km
Concow710 (2011)11.4km
Yankee Hill333 (2011)13.9km
Nearest Clubs:
Local clubs are the best way to get access to collecting localities
ClubLocationDistance
Paradise Gem & Mineral ClubParadise, California5km
Feather River Lapidary & Mineral SocietyOroville, California33km
Mindat Locality ID:
74158
Long-form identifier:
mindat:1:2:74158:0
GUID (UUID V4):
0


A former Cr mine located in sec. 34, T23N, R3E, MDM (location uncertain, assumed spot at center of sec. 34), 1.2 km (3,800 feet) SSE of Irish Town, along Middle Butte Creek. Operated by Rae Helmke, San Francisco, California. MRDS database stated accuracy for this location is 1,000 meters.

Mineralization is hosted in serpentinite. The ore body is lens-shaped. Local rocks include Tertiary pyroclastic and volcanic mudflow deposits, unit 9 (Cascade Range).

A small production was reported in 1947.

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:10028401

Other Regions, Features and Areas containing this locality

North AmericaContinent
North America PlateTectonic Plate
USA

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

(n.d.) Minerals Availability System (MAS), U.S. Bureau of Mines.file ID #0060070057
O’Brien, J.C. (1949), Mines and mineral resources of Butte County, California: California Journal of Mines and Geology (Report 45): 45(3): 421, 444.
(2005) Mineral Resources Data System (MRDS), US Geological Survey.
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