La Primera

The La Primera is a chromium mine located in San Luis Obispo county, California at an elevation of 1,775 feet.

About the MRDS Data:

All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.

Mine Info

Satelite View

MRDS mine locations are often very general, and in some cases are incorrect. Some mine remains have been covered or removed by modern industrial activity or by development of things like housing. The satellite view offers a quick glimpse as to whether the MRDS location corresponds to visible mine remains.

Site Name

Primary: La Primera
Secondary: La Primero
Secondary: Hardface
Secondary: El Primero

Commodity

Primary: Chromium

Location

State: California
County: San Luis Obispo
District: Cuesta Pass

Land Status

Land ownership: Federal
Note: the land ownership field only identifies whether the area the mine is in is generally on public lands like Forest Service or BLM land, or if it is in an area that is generally private property. It does not definitively identify property status, nor does it indicate claim status or whether an area is open to prospecting. Always respect private property.

Holdings

Type: Minerals Only

Workings

Not available

Ownership

Owner Name: Swartz, Arthur
Percent: 100.0
Home Office: California
Info Year: 1976

Owner Name: Pierce Brothers
Home Office: California
Info Year: 1958

Production

Year: 1952
Description: Lump Ore Mined From 1952-1958 280 Mt @ 44.6 Pct-2.6:1 Cr:Fe
Year: 1952
Description: Concentrates Produced From 1952-1958 11400 Mt @ 45.8 Pct-2.3:1 Cr:Fe
Year: 1952
Description: Ore Mined From 1952-1958 37400 Mt
Year: 1880
Description: Lump Ore Mined 250 Mt
Year: 1918
Description: Lump Ore Mined 25 Mt

Deposit

Record Type: Site
Operation Category: Past Producer
Operation Type: Surface-Underground
Mining Method: Unknown
Year First Production: 1890
Discovery Year: 1890
Years of Production:
Organization:
Significant: N
Deposit Size: S

Physiography

General Physiographic Area: Pacific Mountain System
Physiographic Province: Pacific Border Province
Physiographic Section: California Coast Ranges

Mineral Deposit Model

Not available

Orebody

Not available

Structure

Not available

Alterations

Not available

Rocks

Not available

Analytical Data

Not available

Materials

Unknown: Chromite
Unknown: Uvarovite
Unknown: Serpentine
Unknown: Pyroxene
Unknown: Olivine

Comments

Comment (Deposit): 325 TONS WAS SHIPPED PRIOR TO 1918.1952-1958 37,390 LT MILLI MINED,11397 LT.CONCENTRATES PRODUCED. 282 LT.LUMP ORE MINED. ORG RAN 44.6% CR2O3,11.5% FE,CR/FE=2.6.CONCENTRATE RAN 45.8% 13.2 PERCENT CR2O3,CR/FE=2.3. RE-SERVE ESTIMATE-50%=5 FOOT P ION OF EXPOSED ORE,25%=10 FOOT,10%=25 FOOT INADEQUATE RESOURCES FOR COST ANALYSIS. ANALYSIS BY CDMG IN 1976 GAVE FOLLOWING PERCENTAGES-MASSIVE 2 01.57,CR2O3 54.08,FEO 10.37,TOTAL FE 14.15,AL203 14.17,MGO CR/FE 3.36.DISSEMINATE ORE=SI02 14.23,CR2O3 33.62,FEO 09.59 FE 16.72,AL203 13.27,MGO 18.82,CR/FE 1.77.

Comment (Reserve-Resource): MAT 1 COL 1 REPRESENTS AVERAGE ORE GRADE MAT 1 COL 2 REPRESENTS HIGH GRADE ORE MAT 1 COL 3 REPRESENTS LOW GRADE ORE

References

Reference (Deposit): P. 61-63.

Reference (Deposit): CALIF. DIV. MINES BULLETIN 134, 1953, PART II, CHAPT. 2,

Reference (Deposit): CALIF. STATE MINING BUR. BULLETIN 76, 1918, P. 171.

Reference (Deposit): DECEMBER 1993 (P. 6-8).

Reference (Deposit): METAL MINES IN NORTHWEST SAN LUIS OBISPO COUNTY, CA,

Reference (Deposit): COAST REGION. SURFACE WATER DEGRADATION BY INACTIVE

Reference (Deposit): CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD, CENTRAL

California Gold

"Where to Find Gold in California" looks at the density of modern placer mining claims along with historical gold mining locations and mining district descriptions to determine areas of high gold discovery potential in California. Read more: Where to Find Gold in California.