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  3. Mineral Resource Data System (MRDS)

Rianda

Past Producer in Santa Clara county in California, United States with commodity Mercury
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Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Public Land Survey System information
  6. Commodities
  7. Materials information
  8. Alteration
  9. Nearby scientific data
  10. Geologic structures
  11. Ore body information
  12. Controls for ore emplacement
  13. Economic information about the deposit and operations
  14. Ownership information
  15. Production statistics
  16. Workings at the site
  17. Links to other databases
  18. Bibliographic references
  19. Reporter information

Geologic information

Identification information

Deposit ID 10040760
MRDS ID M055627
Record type Site
Current site name Rianda
Alternate or previous names Half Dome
Related records 10116336

Geographic coordinates

Geographic coordinates: -121.5238, 37.05381 (WGS84)
Relative position 5 MI NE OF GILROY

Site location context

Political divisions (FIPS codes)

Santa Clara(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Gilroy(quadrangle 1:24,000 scale)

San Jose(quadrangle 1:100,000 scale)

San Jose(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Pajaro(hydrologic unit)

Central California Coastal(hydrologic accounting unit)

Central California Coastal(hydrologic subregion)

California(hydrologic region)

Geographic areas

Country State County
United States California Santa Clara

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 010S 004E 22 California

Comments on the location information

  • LOCATED AT ADIT

Commodities

Commodity Importance
Mercury Primary

Materials information

Materials Type of material
Cinnabar Ore
Chalcopyrite Gangue
Marcasite Gangue
Pyrite Gangue

Alteration

  • (Local) Silica Carbonate Alteration Of Serpentine

Economic information

Geologic structures

Type of structure Local
Structure description Serpentine - Sandstone Contact, Hayward Fault

Ore body information

  • General form TABULAR

Controls for ore emplacement

  • Altered Serpentine, Contact

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No
Production years 1942 - 1944

Ownership information

  • Type Owner
    Owner Antone A. Rianda

Production statistics

  • Year 1960
    Period To 1960
    Material HG
    Accuracy Estimate
    Description Cp_Grade: ^5-15 Lb/Ton
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Mercury Mercury 4518wt-pct

Workings at the site

  • Type of workings Underground
    Length 304.8M

Reference information

Bibliographic references

  • Deposit

    HOLMES, G. W., JR., 1965, MERCURY IN CALIFORNIA: IN USBM IC 8252

  • Deposit

    BAILEY, E. H., USGS, PERSONAL FILES

  • Deposit

    AVIS, F.F. AND JENNING, C.W., 1954, MINES AND MINERAL RESOURCES OF SANTA CLARA COUNTY, CALIF.: CJMG, V. 50, P. 342-354

  • Production

    USBM DATA

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JUL-1976 Peterson, Jocelyn A. U.S. Geological Survey

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Maps centered on this site

Authoritative California resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.