Mineral Evolution Database
Created and maintained by the Mineral Evolution Project in partnership with RRUFF and mindat.
Mineral locality data provided by mindat.org



The Mineral Evolution database is currently under development.

The goal of this page is to present localities at which the mineral is found, and estimates of the oldest possible geologic age of the minerals at these localities.


Locality Name:
Foresthill, Forest Hill District, Placer Co., California, USA

Oldest recorded age at locality: 388
Youngest recorded age at locality: 388

mindat Locality ID: 85918
mindat URL: http://www.mindat.org/loc-85918.html

Tectonic Settings:

Total number of sublocalities beneath "Foresthill, Forest Hill District, Placer Co., California, USA": 43
Total number of bottom-level sublocalities: 42

Number of Child Localities: 42
Child Localities:
Baltimore Mine
Big Spring Placer Mine
Black Rock Chrome Deposit
California And Virginia Mine (California & Virginia Placer Mines)
Chrome Divide Mine (Mystery Mine)
Dardanelles Placer Mine (Oro & Dardanelles)
Dewey And Stocker Mine (Dewey & Stocker; Burt Mine)
Doherty Mine
Donna's Stake Occurrence
Dry Hill And Blue Jay Mine (Dry Hill Mine)
E. A. Garrison Prospects
El Dorado Mine
Eva Lode Mine
Ferrier Diggings Mine (Johnny Rafael Mine)
Florida & Tilton Placer (Florida)
Homestake Mine [1]
Independent Placer Mine (Jenny Lind Mine; New Jersey Mine)
Iowa Hill Placer
Ladies Canyon Placer
Little Greek Claims
Lucky Strike Mine (Lucky Strike Occurrence [1])
Marigold Placer Mine
Mascot Placer (Excelsior; Baltimore)
Maus Tunnel
Mosquito Ridge Mine (AKA: Unknown)
Moss Ledge Mine
Pegasus Mine
Rio Del Oro Mine
Rough & Ready Placer
Sellier Mine
Three Queens Mine (Four Acres Mine)
Thundering Bar Placer Mine
Two Unnamed Au Prospects [1]
Unnamed Au Location [2]
Unnamed Au Mine [3]
Unnamed Au Mine [34]
Unnamed Au Prospect [4]
Unnamed Au Prospect [5]
Unnamed Au Prospects [89]
Unspecified Diamond Occurrences [1]
Washington Mine
West Quartz Mine

Latitude: 39°1'0"N
Longitude: 120°48'7"W
Decimal Degree (lat, lon): 39.016666666667,-120.80194444444
AThis mineral is Anthropogenic.
GThis mineral is directly dated.
BThis mineral is reported as having this age.
YThis mineral is using an age reported as an element mineralization period.
OThis mineral is using an age calculated from all data at the locality.
RThe age displayed for this mineral originates from a different, non-child locality.
PThe age displayed for this mineral is the range of ages for this mineral at all of this locality's children.
This mineral's age has not yet been recorded.

This Mineral list contains entries from this locality, including sub-localities. Minerals in bold are reported by mindat.org as occurring directly at this locality, and do not occur at any children (sublocalities) of this locality.

Elements at this locality, including sub-localities: Au C Ca Cr Fe H Mg Mn O Si 

Elements from minerals reported directly at this locality: Ca Mn O Si 

Structural Groups for minerals in this locality: 
ClayCopperDiamondNoneQuartzRhodoniteSpinelTalc

8 IMA Minerals at location:
Ankerite  (*)Chromite  (*)Diamond  (*)Gold  (*)Graphite  (*)
Quartz  (*)Rhodonite  (*)Talc  (*)
Mineral nameStructural GroupsIMA FormulaMax Age (Ma)Min Age (Ma)# of Sublocalities containing mineralLOCALITY IDs, not mindat ids# of localities containing mineral
Ankerite  (*)NoneCa(Fe2+,Mg)(CO3)22166958,1669823092
Chromite  (*)SpinelFe2+Cr2O43883884166953,166955,166970,1669713902
Diamond  (*)DiamondC1166991697
Gold  (*)CopperAu15166952,166957,166958,166960,166963,166964,166965,166967,166972,166974,166982,166983,166986,166992,16699330554
Graphite  (*)NoneC11669822812
Quartz  (*)QuartzSiO210166957,166958,166960,166963,166964,166982,166984,166986,166992,16699361156
Rhodonite  (*)RhodoniteCaMn3Mn(Si5O15)3883880969
Talc  (*)Clay TalcMg3Si4O10(OH)211669823337


1 Ages assigned to this locality:

Excel IDMax Age (Ma)Min Age (Ma)Age as listed in referenceDating MethodAge InterpretPrioritized?Sample SourceSample NumRun NumAge from other LocalityDated MineralMinerals explicitely stated as having this ageAge applies to these ElementsMinDat Locality IDDated Locality (Max Age)Location as listed in referenceReferenceReference DOIReference IDAge Notes
podchrome-00156388388pre-Early Devonian-Jurassic (388±17 Ma U-Pb zircon from felsic igneous rocks; 174 Ma K-Ar white mica from blueschists)       Cr85103Black Rock Chrome Deposit, Foresthill, Forest Hill District, Placer Co., California, USABlack Rock ChromeMoiser et al. (2012) USGSSIR2012_5157 

SampleSource LocalityReference URL

All locality data graciously provided by mindat.org

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