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Commodore Mine (Golden Gate Mine), San Andreas, San Andreas Mining District, Calaveras County, California, USAi
Regional Level Types
Commodore Mine (Golden Gate Mine)Mine
San AndreasCensus-designated Place
San Andreas Mining DistrictMining District
Calaveras CountyCounty
CaliforniaState
USACountry

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Latitude & Longitude (WGS84):
38° 12' 36'' North , 120° 41' 52'' West
Latitude & Longitude (decimal):
Type:
Nearest Settlements:
PlacePopulationDistance
San Andreas2,783 (2011)2.2km
Mokelumne Hill646 (2011)10.1km
Valley Springs3,553 (2011)11.7km
Mountain Ranch1,628 (2011)13.9km
Rancho Calaveras4,489 (2018)16.8km
Nearest Clubs:
Local clubs are the best way to get access to collecting localities
ClubLocationDistance
Calaveras Gem & Mineral SocietyAngels Camp, California21km
Amador County Gem & Mineral SocietySutter Creek, California22km
Mindat Locality ID:
75072
Long-form identifier:
mindat:1:2:75072:8
GUID (UUID V4):
0


A former lode Au mine located in the SW¼ sec. 7, T4N, R12E, MDM, 2.2 km (7,300 feet/1.3 miles) NW of San Andreas at Carson Hill. Operated during the periods 1899 to October 1900, and July 1933 to September, 1934. MRDS database stated accuracy for this location is 500 meters.

Mineralization is hosted in quartz diorite. The Commodore East vein was reported as a quartz diorite intrusive. A section from W to E gives: amphibolite schist, ankerite, a quartz vein, a wide body of ankerite, and serpentine, a mineralized quartz diorite intrusion which is the Commodore vein, serpentine and diabase. A 4 foot thick zone of crushed material from which rhombic crystals of dolomite contained visible gold particles, is on the hanging wall side of the quartz diorite. Local rocks include Paleozoic metavolcanic rocks, unit 4 (Western Sierra Nevada Foothills) and/or Jurassic marine rocks, unit 1 (Western Sierra Nevada and Western Klamath Mountains).

Workings include underground openings comprised of a 300 foot deep shaft with several levels (80, 200 & 300 feet), drifts and crosscuts, which include a 450 foot adit, 80, 200 & 300 . The working shaft is vertical for the first 80 feet, thereafter the remainder is at an incline of 75 degrees.

Production data are found in: Clark, Wm. B. & P.A. Lydon (1962).

Production data: $7 (period values) per ton ore encountered to the N at 300 foot level. No production record found.

Analytical data results: Ore averaged $4 (period values) per ton Au (mill test - 1900).

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List


5 valid minerals.

Detailed Mineral List:

Ankerite
Formula: Ca(Fe2+,Mg)(CO3)2
Dolomite
Formula: CaMg(CO3)2
Muscovite
Formula: KAl2(AlSi3O10)(OH)2
Description: Occurs in schist.
Muscovite var. Mariposite
Formula: K(Al,Cr)2(Al,Si)4O10(OH)2
Description: Occurs in schist.
Muscovite var. Phengite
Formula: KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2
Description: Occurs in schist.
Native Gold
Formula: Au
Quartz
Formula: SiO2
'Serpentine Subgroup'
Formula: D3[Si2O5](OH)4

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 1 - Elements
Native Gold1.AA.05Au
Group 4 - Oxides and Hydroxides
Quartz4.DA.05SiO2
Group 5 - Nitrates and Carbonates
Ankerite5.AB.10Ca(Fe2+,Mg)(CO3)2
Dolomite5.AB.10CaMg(CO3)2
Group 9 - Silicates
Muscovite9.EC.15KAl2(AlSi3O10)(OH)2
var. Phengite9.EC.15KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2
var. Mariposite9.EC.15K(Al,Cr)2(Al,Si)4O10(OH)2
Unclassified
'Serpentine Subgroup'-D3[Si2O5](OH)4

List of minerals for each chemical element

HHydrogen
H MuscoviteKAl2(AlSi3O10)(OH)2
H Muscovite var. PhengiteKAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2
H Muscovite var. MaripositeK(Al,Cr)2(Al,Si)4O10(OH)2
H Serpentine SubgroupD3[Si2O5](OH)4
CCarbon
C AnkeriteCa(Fe2+,Mg)(CO3)2
C DolomiteCaMg(CO3)2
OOxygen
O AnkeriteCa(Fe2+,Mg)(CO3)2
O DolomiteCaMg(CO3)2
O MuscoviteKAl2(AlSi3O10)(OH)2
O Muscovite var. PhengiteKAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2
O QuartzSiO2
O Muscovite var. MaripositeK(Al,Cr)2(Al,Si)4O10(OH)2
O Serpentine SubgroupD3[Si2O5](OH)4
MgMagnesium
Mg AnkeriteCa(Fe2+,Mg)(CO3)2
Mg DolomiteCaMg(CO3)2
Mg Muscovite var. PhengiteKAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2
AlAluminium
Al MuscoviteKAl2(AlSi3O10)(OH)2
Al Muscovite var. PhengiteKAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2
Al Muscovite var. MaripositeK(Al,Cr)2(Al,Si)4O10(OH)2
SiSilicon
Si MuscoviteKAl2(AlSi3O10)(OH)2
Si Muscovite var. PhengiteKAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2
Si QuartzSiO2
Si Muscovite var. MaripositeK(Al,Cr)2(Al,Si)4O10(OH)2
Si Serpentine SubgroupD3[Si2O5](OH)4
KPotassium
K MuscoviteKAl2(AlSi3O10)(OH)2
K Muscovite var. PhengiteKAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2
K Muscovite var. MaripositeK(Al,Cr)2(Al,Si)4O10(OH)2
CaCalcium
Ca AnkeriteCa(Fe2+,Mg)(CO3)2
Ca DolomiteCaMg(CO3)2
CrChromium
Cr Muscovite var. MaripositeK(Al,Cr)2(Al,Si)4O10(OH)2
FeIron
Fe AnkeriteCa(Fe2+,Mg)(CO3)2
Fe Muscovite var. PhengiteKAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2
AuGold
Au Native GoldAu

Other Databases

Link to USGS MRDS:10102657

Other Regions, Features and Areas containing this locality

North AmericaContinent
North America PlateTectonic Plate
USA

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