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Placerville (Hangtown), Placerville District, Mother Lode Belt, El Dorado Co., California, USAi
Regional Level Types
Placerville (Hangtown)- not defined -
Placerville DistrictMining District
Mother Lode BeltBelt
El Dorado Co.County
CaliforniaState
USACountry

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Latitude & Longitude (WGS84): 38° 43' 47'' North , 120° 47' 51'' West
Latitude & Longitude (decimal): 38.72972,-120.79750
GeoHash:G#: 9qfh74tby
Köppen climate type:Csa : Hot-summer Mediterranean climate
Nearest Settlements:
PlacePopulationDistance
Placerville10,650 (2017)0.1km
Diamond Springs11,037 (2011)4.2km
Deer Park1,384 (2018)5.8km
Cold Springs446 (2011)6.4km
Camino1,750 (2011)10.7km


Placerville was originally named "Hangtown."

Regions containing this locality

North America PlateTectonic Plate

Select Mineral List Type

Standard Detailed Strunz Dana Chemical Elements

Mineral List

Mineral list contains entries from the region specified including sub-localities

16 valid minerals.

Detailed Mineral List:

Anatase
Formula: TiO2
Description: Occurs as minute crystals with brookite on quartz crystals.
Reference: Kunz, George Frederick (1892), Mineralogical notes on brookite, octahedrite, quartz, and ruby: American Journal of Science, 3rd. series: 43: 329-330; Kunz, George Frederick (1892), Octahedrite (anatase) near Placerville, El Dorado County: Mineralogical Magazine: 9: 395; Kunz, George Frederick (1893), Mineralogical notes on brookite, octahedrite, and quartz: California Mining Bureau. Report 11: 207-209; Kunz, George Frederick (1901), Octahedrite (anatase) from Placerville, El Dorado County: Mineralogical Magazine: 9: 394; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 72, 114.
Arsenopyrite
Formula: FeAsS
Reference: USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10310663.
Brookite
Formula: TiO2
Reference: Kunz, George Frederick (1892), Mineralogical notes on brookite, octahedrite, quartz, and ruby: American Journal of Science, 3rd. series: 43: 329-330; Kunz, George Frederick (1892), Octahedrite (anatase) near Placerville, El Dorado County: Mineralogical Magazine: 9: 395; Kunz, George Frederick (1893), Mineralogical notes on brookite, octahedrite, and quartz: California Mining Bureau. Report 11: 207-209; Kunz, George Frederick (1901), Octahedrite (anatase) from Placerville, El Dorado County: Mineralogical Magazine: 9: 394; Kunz, George Frederick (1905a), Gems, jewelers’ materials, and ornamental stones of California: California Division Mines Bulletin 37, 171 pp.: 106; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 72, 114.
Carnotite
Formula: K2(UO2)2(VO4)2 · 3H2O
Description: Represented by California Division of Mines and Geology specimen #21635.
Reference: Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 120.
Clinochlore
Formula: Mg5Al(AlSi3O10)(OH)8
Reference: Knopf, Adolf (1929), The Mother Lode system of California: USGS PP 157, 88 pp: 37; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 434.
Clinochlore var: Ripidolite
Formula: (Mg,Fe,Al)6(Si,Al)4O10(OH)8
Reference: Knopf, Adolf (1929), The Mother Lode system of California: USGS PP 157, 88 pp: 37; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 434.
Diamond
Formula: C
Description: 3 or 4 stones found at about ½ - 1¼ carets.
Reference: Hanks, Henry Garber (1882b), Diamonds in California: California Mining Bureau. Report 2: 250; Hanks, Henry Garber (1884), Fourth report of the State Mineralogist: California Mining Bureau. Report 4, 410 pp. (includes catalog of minerals of California pp. 63-410), and miscellaneous observations on mineral products): 168, 169; Kunz, George Frederick (1905a), Gems, jewelers’ materials, and ornamental stones of California: California Division Mines Bulletin 37, 171 pp.: 44.
Galena
Formula: PbS
Gold
Formula: Au
Localities: Reported from at least 59 localities in this region.
Graphite
Formula: C
Description: Occurs as graphitic slate.
Reference: USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10101129.
Maldonite
Formula: Au2Bi
Description: Founf in 1899 and represented by CDMG specimen #15391. 60% Au & 40% Bi.
Reference: Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 106; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 18 (map 2-7), 37; Bernard, Jan H.and Jaroslav Hyrsl (2004), Minerals and their Localities: 374.
'Manganese Oxides'
Reference: USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10030182.
'Mariposite'
Formula: K(Al,Cr)2(Al,Si)4O10(OH)2
Reference: William H. Storms, California State Mining Bureau. 1900. The Mother Lode Region of California. Page 20.
Molybdenite
Formula: MoS2
Reference: Trask, John Boardman (1856), Report on the geology of northern and southern California: California Legislature, 7th. sess., Ap. to Jour. S. Doc. 14, 66 pp.: 28; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 268.
Muscovite
Formula: KAl2(AlSi3O10)(OH)2
Reference: William H. Storms, California State Mining Bureau. 1900. The Mother Lode Region of California. Page 20.
Muscovite var: Phengite
Formula: KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2
Reference: William H. Storms, California State Mining Bureau. 1900. The Mother Lode Region of California. Page 20.
Pyrite
Formula: FeS2
Pyrite var: Auriferous Pyrite
Formula: FeS2
Reference: USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10310663.
Quartz
Formula: SiO2
Localities: Reported from at least 36 localities in this region.
Quartz var: Rock Crystal
Formula: SiO2
Description: Includes phantoms; best in the state.
Reference: Hanks, Henry Garber (1884), Fourth report of the State Mineralogist: California Mining Bureau. Report 4, 410 pp.: 65; Kunz, George Frederick (1892), Mineralogical notes on brookite, octahedrite, quartz, and ruby: American Journal of Science, 3rd. series: 43: 329-330; Kunz, George Frederick (1892), Octahedrite (anatase) near Placerville, El Dorado County: Mineralogical Magazine: 9: 395; Kunz, George Frederick (1893), Precious stones: Mineral Resources U.S., 1891: 547; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 313.
Quartz var: Smoky Quartz
Formula: SiO2
Reference: Hanks, Henry Garber (1884), Fourth report of the State Mineralogist: California Mining Bureau. Report 4, 410 pp.: 65; Kunz, George Frederick (1892), Mineralogical notes on brookite, octahedrite, quartz, and ruby: American Journal of Science, 3rd. series: 43: 329-330; Kunz, George Frederick (1892), Octahedrite (anatase) near Placerville, El Dorado County: Mineralogical Magazine: 9: 395; Kunz, George Frederick (1893), Precious stones: Mineral Resources U.S., 1891: 547; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 313.
Silver
Formula: Ag
Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Talc
Formula: Mg3Si4O10(OH)2
Reference: Emmons and Becker (1885) Statistics and Technology of the precious Metals. Census reports Tenth census. June 1, 1880, Volume 13 By United States. Census office. 10th census, 1880, United States. Census Office

List of minerals arranged by Strunz 10th Edition classification

Group 1 - Elements
Diamond1.CB.10aC
Gold1.AA.05Au
Graphite1.CB.05aC
Silver1.AA.05Ag
Group 2 - Sulphides and Sulfosalts
Arsenopyrite2.EB.20FeAsS
Galena2.CD.10PbS
Maldonite2.AA.40Au2Bi
Molybdenite2.EA.30MoS2
Pyrite2.EB.05aFeS2
var: Auriferous Pyrite2.EB.05aFeS2
Group 4 - Oxides and Hydroxides
Anatase4.DD.05TiO2
Brookite4.DD.10TiO2
Carnotite4.HB.05K2(UO2)2(VO4)2 · 3H2O
Quartz4.DA.05SiO2
var: Rock Crystal4.DA.05SiO2
var: Smoky Quartz4.DA.05SiO2
Group 9 - Silicates
Clinochlore9.EC.55Mg5Al(AlSi3O10)(OH)8
var: Ripidolite9.EC.55(Mg,Fe,Al)6(Si,Al)4O10(OH)8
Muscovite9.EC.15KAl2(AlSi3O10)(OH)2
var: Phengite9.EC.15KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2
Talc9.EC.05Mg3Si4O10(OH)2
Unclassified Minerals, Rocks, etc.
'Manganese Oxides'-
'Mariposite'-K(Al,Cr)2(Al,Si)4O10(OH)2

List of minerals arranged by Dana 8th Edition classification

Group 1 - NATIVE ELEMENTS AND ALLOYS
Metals, other than the Platinum Group
Gold1.1.1.1Au
Maldonite1.1.3.1Au2Bi
Silver1.1.1.2Ag
Semi-metals and non-metals
Diamond1.3.6.1C
Graphite1.3.6.2C
Group 2 - SULFIDES
AmXp, with m:p = 1:1
Galena2.8.1.1PbS
AmBnXp, with (m+n):p = 1:2
Arsenopyrite2.12.4.1FeAsS
Molybdenite2.12.10.1MoS2
Pyrite2.12.1.1FeS2
Group 4 - SIMPLE OXIDES
AX2
Anatase4.4.4.1TiO2
Brookite4.4.5.1TiO2
Group 40 - HYDRATED NORMAL PHOSPHATES,ARSENATES AND VANADATES
AB2(XO4)2·xH2O, containing (UO2)2+
Carnotite40.2a.28.1K2(UO2)2(VO4)2 · 3H2O
Group 71 - PHYLLOSILICATES Sheets of Six-Membered Rings
Sheets of 6-membered rings with 2:1 layers
Muscovite71.2.2a.1KAl2(AlSi3O10)(OH)2
Talc71.2.1.3Mg3Si4O10(OH)2
Sheets of 6-membered rings interlayered 1:1, 2:1, and octahedra
Clinochlore71.4.1.4Mg5Al(AlSi3O10)(OH)8
Group 75 - TECTOSILICATES Si Tetrahedral Frameworks
Si Tetrahedral Frameworks - SiO2 with [4] coordinated Si
Quartz75.1.3.1SiO2
Unclassified Minerals, Mixtures, etc.
Clinochlore
var: Ripidolite
-(Mg,Fe,Al)6(Si,Al)4O10(OH)8
'Manganese Oxides'-
'Mariposite'-K(Al,Cr)2(Al,Si)4O10(OH)2
Muscovite
var: Phengite
-KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2
Pyrite
var: Auriferous Pyrite
-FeS2
Quartz
var: Rock Crystal
-SiO2
var: Smoky Quartz-SiO2

List of minerals for each chemical element

HHydrogen
H Clinochlore (var: Ripidolite)(Mg,Fe,Al)6(Si,Al)4O10(OH)8
H CarnotiteK2(UO2)2(VO4)2 · 3H2O
H TalcMg3Si4O10(OH)2
H MaripositeK(Al,Cr)2(Al,Si)4O10(OH)2
H ClinochloreMg5Al(AlSi3O10)(OH)8
H MuscoviteKAl2(AlSi3O10)(OH)2
H Muscovite (var: Phengite)KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2
CCarbon
C DiamondC
C GraphiteC
OOxygen
O QuartzSiO2
O Clinochlore (var: Ripidolite)(Mg,Fe,Al)6(Si,Al)4O10(OH)8
O AnataseTiO2
O BrookiteTiO2
O CarnotiteK2(UO2)2(VO4)2 · 3H2O
O Quartz (var: Rock Crystal)SiO2
O Quartz (var: Smoky Quartz)SiO2
O TalcMg3Si4O10(OH)2
O MaripositeK(Al,Cr)2(Al,Si)4O10(OH)2
O ClinochloreMg5Al(AlSi3O10)(OH)8
O MuscoviteKAl2(AlSi3O10)(OH)2
O Muscovite (var: Phengite)KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2
MgMagnesium
Mg Clinochlore (var: Ripidolite)(Mg,Fe,Al)6(Si,Al)4O10(OH)8
Mg TalcMg3Si4O10(OH)2
Mg ClinochloreMg5Al(AlSi3O10)(OH)8
Mg Muscovite (var: Phengite)KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2
AlAluminium
Al Clinochlore (var: Ripidolite)(Mg,Fe,Al)6(Si,Al)4O10(OH)8
Al MaripositeK(Al,Cr)2(Al,Si)4O10(OH)2
Al ClinochloreMg5Al(AlSi3O10)(OH)8
Al MuscoviteKAl2(AlSi3O10)(OH)2
Al Muscovite (var: Phengite)KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2
SiSilicon
Si QuartzSiO2
Si Clinochlore (var: Ripidolite)(Mg,Fe,Al)6(Si,Al)4O10(OH)8
Si Quartz (var: Rock Crystal)SiO2
Si Quartz (var: Smoky Quartz)SiO2
Si TalcMg3Si4O10(OH)2
Si MaripositeK(Al,Cr)2(Al,Si)4O10(OH)2
Si ClinochloreMg5Al(AlSi3O10)(OH)8
Si MuscoviteKAl2(AlSi3O10)(OH)2
Si Muscovite (var: Phengite)KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2
SSulfur
S PyriteFeS2
S GalenaPbS
S MolybdeniteMoS2
S Pyrite (var: Auriferous Pyrite)FeS2
S ArsenopyriteFeAsS
KPotassium
K CarnotiteK2(UO2)2(VO4)2 · 3H2O
K MaripositeK(Al,Cr)2(Al,Si)4O10(OH)2
K MuscoviteKAl2(AlSi3O10)(OH)2
K Muscovite (var: Phengite)KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2
TiTitanium
Ti AnataseTiO2
Ti BrookiteTiO2
VVanadium
V CarnotiteK2(UO2)2(VO4)2 · 3H2O
CrChromium
Cr MaripositeK(Al,Cr)2(Al,Si)4O10(OH)2
FeIron
Fe PyriteFeS2
Fe Clinochlore (var: Ripidolite)(Mg,Fe,Al)6(Si,Al)4O10(OH)8
Fe Pyrite (var: Auriferous Pyrite)FeS2
Fe ArsenopyriteFeAsS
Fe Muscovite (var: Phengite)KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2
AsArsenic
As ArsenopyriteFeAsS
MoMolybdenum
Mo MolybdeniteMoS2
AgSilver
Ag SilverAg
AuGold
Au GoldAu
Au MaldoniteAu2Bi
PbLead
Pb GalenaPbS
BiBismuth
Bi MaldoniteAu2Bi
UUranium
U CarnotiteK2(UO2)2(VO4)2 · 3H2O

Regional Geology

This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.

Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org

Late Jurassic - Triassic
145 - 251.902 Ma



ID: 2902371
Jurassic marine rocks, unit 1 (Western Sierra Nevada and Western Klamath Mountains)

Age: Mesozoic (145 - 251.902 Ma)

Stratigraphic Name: Agua Fria Formation; Colfax Formation; Cosumnes Formation; Galice Formation; Hunter Valley Cherts; Mariposa Formation; Merced Falls Slate; Salt Spring Slate; Jasper Point Formation

Description: Shale, sandstone, minor conglomerate, chert, slate, limestone; minor pyroclastic rocks

Comments: Western Klamath Mountains, western Sierra Nevada. Primarily slate and metamorphosed graywacke; minor siltstone, conglomerate, chert, and volcanic rocks. Mainly Late Jurassic in age, but also includes some Early Jurassic or older rocks Original map source: Saucedo, G.J., Bedford, D.R., Raines, G.L., Miller, R.J., and Wentworth, C.M., 2000, GIS Data for the Geologic Map of California, California Department of Conservation, Division of Mines and Geology, CD-ROM 2000-07, scale 1:750,000.

Lithology: Major:{slate,graywacke}, Minor:{siltstone,conglomerate}, Incidental:{chert, volcanic, basalt}

Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052. [133]

Devonian - Silurian
358.9 - 443.8 Ma



ID: 3185269
Paleozoic sedimentary and volcanic rocks

Age: Paleozoic (358.9 - 443.8 Ma)

Comments: Mccloud Arc

Lithology: Mudstone-carbonate-sandstone-conglomerate

Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529. [154]

Data and map coding provided by Macrostrat.org, used under Creative Commons Attribution 4.0 License

Localities in this Region
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