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El Dorado Co., California, USAi
Regional Level Types
El Dorado Co.County
CaliforniaState
USACountry

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Key
Locality type:
Largest Settlements:
PlacePopulation
El Dorado Hills42,108 (2011)
South Lake Tahoe21,706 (2017)
Cameron Park18,228 (2011)
Diamond Springs11,037 (2011)
Placerville10,650 (2017)
Pollock Pines6,871 (2017)
Other Languages:
French:
Comté d'El Dorado, Californie, États-Unis
German:
El Dorado County, Kalifornien, Vereinigte Staaten
Italian:
Contea di El Dorado, California, Stati Uniti d'America
Russian:
Эль-Дорадо, Калифорния, Соединённые Штаты Америки
Simplified Chinese:
埃尔多拉多县, 加利福尼亚州, 美国
Spanish:
Condado de El Dorado, California, Estados Unidos
Albanian:
El Dorado County, Kalifornia, Shtetet e Bashkuara të Amerikës
Arabic:
مقاطعة إل دورادو, كاليفورنيا, الولايات المتحدة
Armenian:
Էլ Դորադո շրջան, Կալիֆոռնիա, Ամերիկայի Միացյալ Նահանգներ
Basque:
El Dorado konderria, Kalifornia
Bavarian:
El Dorado County, Kalifornien, Vaoanigte Stootn
Bishnupriya Manipuri:
এল ডোরাডো কাউন্টি, ক্যালিফোর্নিয়া, তিলপারাষ্ট্র
Bulgarian:
Ел Дорадо, Калифорния, Съединени американски щати
Cebuano:
El Dorado County, California
Czech:
El Dorado County, Kalifornie, Spojené státy americké
Danish:
El Dorado County, Californien, USA
Dutch:
El Dorado County, Verenigde Staten
Estonian:
El Dorado maakond, California, Ameerika Ühendriigid
Farsi/Persian:
شهرستان ال دورادو، کالیفرنیا, کالیفرنیا, ایالات متحده آمریکا
Galician:
Condado de El Dorado, California, Estados Unidos de América
Hungarian:
El Dorado megye, Kalifornia, Amerikai Egyesült Államok
Icelandic:
El Dorado County, Kalifornía, Bandaríkin
Irish Gaelic:
Contae El Dorado, California, Stáit Aontaithe Mheiriceá
Japanese:
エルドラド郡, カリフォルニア州, アメリカ合衆国
Kapampangan:
El Dorado County, California, Estados Unidos
Latin:
El Dorado Comitatus, California, Civitates Foederatae Americae
Limburgian:
El Dorado County, Californië, Vereinegde Staote vaan Amerika
Low Saxon/Low German:
El Dorado County, Kalifornien, USA
Malayalam:
എൽ ഡോറാഡോ കൗണ്ടി, കാലിഫോർണിയ
Norwegian:
El Dorado County, California, USA
Occitan:
Comtat d'El Dorado, Califòrnia, Estats Units d'America
Polish:
Hrabstwo El Dorado, Kalifornia, Stany Zjednoczone
Portuguese:
Condado de El Dorado, Califórnia, Estados Unidos
Romanian:
Comitatul El Dorado, California, Statele Unite ale Americii
Serbian:
Округ Ел Дорејдо, Калифорнија, Сједињене Америчке Државе
Serbo-Croatian:
El Dorado County, Kalifornija, Sjedinjene Američke Države
Swedish:
El Dorado County, Kalifornien, USA
Tagalog:
El Dorado County, California, Estados Unidos
Turkish:
El Dorado County, Kaliforniya, Amerika Birleşik Devletleri
Ukrainian:
Ель-Дорадо, Каліфорнія, Сполучені Штати Америки
Urdu:
ایل دورادو کاؤنٹی، کیلیفورنیا, کیلیفورنیا, ریاستہائے متحدہ امریکا
Vietnamese:
Quận El Dorado, California, Chủng Quốc Hoa Kỳ
Waray:
Condado han El Dorado, California, Estados Unidos
Western Punjabi:
ال ڈوراڈو کاؤنٹی, کیلیفورنیا, امریکہ


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Standard Detailed Strunz Dana Chemical Elements

Commodity List

This is a list of exploitable or exploited mineral commodities recorded from this region.


Mineral List

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

102 valid minerals. 1 (TL) - type locality of valid minerals.

Rock Types Recorded

Note: this is a very new system on mindat.org and data is currently VERY limited. Please bear with us while we work towards adding this information!

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

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Alphabetical List Tree Diagram

Detailed Mineral List:

Actinolite
Formula: ☐{Ca2}{Mg4.5-2.5Fe0.5-2.5}(Si8O22)(OH)2
Albite
Formula: Na(AlSi3O8)
Anatase
Formula: TiO2
Ankerite
Formula: Ca(Fe2+,Mg)(CO3)2
Antigorite
Formula: Mg3(Si2O5)(OH)4
Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Antimony
Formula: Sb
Reference: Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 77.
Arsenopyrite
Formula: FeAsS
Localities: Reported from at least 9 localities in this region.
Description: Occurs in many Mother Lode mines in the county.
Reference: Logan, Clarence August (1934), Mother Lode Gold Belt of California: California Division Mines Bulletin 108, 221 pp.: 34; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 86.
'Axinite Group'
Colour: Violet
Description: Thin-bladed masses in veins.
Reference: Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 91; Pemberton, H. Earl (1983), Minerals of California: 505.
Axinite-(Mn)
Formula: Ca2Mn2+Al2BSi4O15(OH)
Colour: Brown
Description: Occurs as small clear crystals on epidote.
Reference: Schaller, Waldemar Theodore (1911b), Axinite from California: USGS Bulletin 490: 42; Tucker, W. Burling & C.A. Waring (1919), El Dorado County: California Mining Bureau. Report 15: 276-278; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 65, 91, 175.
Azurite
Formula: Cu3(CO3)2(OH)2
Bornite
Formula: Cu5FeS4
Localities: Reported from at least 11 localities in this region.
Brochantite
Formula: Cu4(SO4)(OH)6
Description: Occurs as rough crystal masses with Chalcopyrite and Quartz.
Reference: Pemberton, H. Earl (1983), Minerals of California: 297.
Brookite
Formula: TiO2
Cacoxenite
Formula: Fe3+24AlO6(PO4)17(OH)12 · 75H2O
Description: Occurs as micro-balls and radiating spheres perched on wavellite.
Reference: Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 304, 313; www.mineralsocal.org
Calaverite
Formula: AuTe2
Reference: Palache, Charles, Harry Berman & Clifford Frondel (1944), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Volume I. John Wiley and Sons, Inc., New York. 7th edition: 336; Clark, Wm. B. & D.W. Carlson (1956), Mines and mineral resources of El Dorado County, California: California Journal of Mines and Geology: 52(4): 496; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 116, 286; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 109, 110.; Irelan, W. jr. (1893) Report of the state mineralogist, Issue 11
Calcite
Formula: CaCO3
Localities: Reported from at least 21 localities in this region.
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.
Chalcanthite
Formula: CuSO4 · 5H2O
Reference: Jay Buscio; Maggie Wilson
Chalcocite
Formula: Cu2S
Chalcopyrite
Formula: CuFeS2
Localities: Reported from at least 31 localities in this region.
'Chlorite Group'
Localities: Reported from at least 9 localities in this region.
Chromite
Formula: Fe2+Cr3+2O4
Localities: Reported from at least 71 localities in this region.
Chrysotile
Formula: Mg3(Si2O5)(OH)4
Cinnabar
Formula: HgS
Description: Occurs interstitially in slate and quartzite.
Reference: Clark, Wm. B. & D.W. Carlson (1956), Mines and mineral resources of El Dorado County, California: California Journal of Mines and Geology: 52(4): 438; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 114.
Clinochlore
Formula: Mg5Al(AlSi3O10)(OH)8
Localities: Reported from at least 16 localities in this region.
Clinochlore var: Chromian Clinochlore
Formula: Mg5(Al,Cr)2Si3O10(OH)8
Localities: Reported from at least 11 localities in this region.
Clinochlore var: Pennine
Formula: Mg5Al(AlSi3O10)(OH)8
Clinochlore var: Ripidolite
Formula: (Mg,Fe,Al)6(Si,Al)4O10(OH)8
Clinochlore var: Sheridanite
Formula: (Mg,Al,Fe)6(Si,Al)4O10(OH)8
Reference: Post, J.L. and Plummer, C.C. (1972) The chlorite series of Flagstaff Hill area, California. Clays and Clay Minerals: 20: 271-283; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 433.
Copper
Formula: Cu
'Copper Stain'
Reference: USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10030338.
Corundum
Formula: Al2O3
Reference: Zhao, X., Lin,Y., Yin,Q.-Z., Zhang, J., Hao, J., Zolensky, M. & Jenniskens, P. (2014) Presolar grains in the CM2 chondrite Sutter's Mill. Meteoritics & Planetary Science 49(11): 2038-2046) (Nov 2014)
Covellite
Formula: CuS
Reference: Pemberton, H. Earl (1983), Minerals of California: 99.
Crandallite
Formula: CaAl3(PO4)(PO3OH)(OH)6
Colour: Light buff to white
Description: Sugary.
Reference: Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 304; www.mineralsocal.org
Cronstedtite
Formula: Fe2+2Fe3+((Si,Fe3+)2O5)(OH)4
Reference: Zolensky, M. & 21 others (2014) Mineralogy and petrography of C asteroid regolith: The Sutter's Mill CM meteorite. Meteoritics & Planetary Science 49(11): 1997-2016. (Nov 2014)
Diamond
Formula: C
Diopside
Formula: CaMgSi2O6
Localities:
Diopside var: Diallage
Formula: CaMgSi2O6
Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Dolomite
Formula: CaMg(CO3)2
Reference: Zolensky, M. & 21 others (2014) Mineralogy and petrography of C asteroid regolith: The Sutter's Mill CM meteorite. Meteoritics & Planetary Science 49(11): 1997-2016. (Nov 2014); Zhao, X., Lin,Y., Yin,Q.-Z., Zhang, J., Hao, J., Zolensky, M. & Jenniskens, P. (2014) Presolar grains in the CM2 chondrite Sutter's Mill. Meteoritics & Planetary Science 49(11): 2038-2046) (Nov 2014)
Enargite
Formula: Cu3AsS4
Reference: Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 175.
Enstatite
Formula: MgSiO3
Epidote
Formula: {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Localities: Reported from at least 10 localities in this region.
'Fayalite-Forsterite Series'
Localities: Reported from at least 8 localities in this region.
'Feldspar Group'
Ferrimolybdite
Formula: Fe2(MoO4)3 · nH2O
Reference: Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 185; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 341.
Forsterite
Formula: Mg2SiO4
Reference: Zolensky, M. & 21 others (2014) Mineralogy and petrography of C asteroid regolith: The Sutter's Mill CM meteorite. Meteoritics & Planetary Science 49(11): 1997-2016. (Nov 2014)
Galena
Formula: PbS
Localities: Reported from at least 22 localities in this region.
'Garnet Group'
Formula: X3Z2(SiO4)3
Localities: Reported from at least 8 localities in this region.
'Garnierite'
Gold
Formula: Au
Localities: Reported from at least 623 localities in this region.
Graphite
Formula: C
Grossular
Formula: Ca3Al2(SiO4)3
Gypsum
Formula: CaSO4 · 2H2O
Reference: USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10037742.
Halotrichite
Formula: FeAl2(SO4)4 · 22H2O
Reference: Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 213.
Hedenbergite
Formula: CaFe2+Si2O6
Reference: Zolensky, M. & 21 others (2014) Mineralogy and petrography of C asteroid regolith: The Sutter's Mill CM meteorite. Meteoritics & Planetary Science 49(11): 1997-2016. (Nov 2014)
Hematite
Formula: Fe2O3
Localities: Reported from at least 6 localities in this region.
Hematite var: Specularite
Formula: Fe2O3
Reference: USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10029902.
Hessite
Formula: Ag2Te
Hinsdalite
Formula: PbAl3(PO4)(SO4)(OH)6
Colour: Golden yellow to greenish yellow.
Description: Occurs as flakes and masses on quartz.
Reference: Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 307.
'Hornblende'
Ilmenite
Formula: Fe2+TiO3
Description: Occurs in placer sands including as beautiful and complex crystals with brilliant faces to 1 inch (2.5 cm) diameter.
Reference: Blake, Wm. P. (1858), Report of a geological reconnaissance in California 370 pp., New York: 303; Hanks, Henry Garber (1884), Fourth report of the State Mineralogist: California Mining Bureau. Report 4, 410 pp.: 260.; Kunz, George Frederick (1905a), Gems, jewelers’ materials, and ornamental stones of California: California Division Mines Bulletin 37, 171 pp.: 105; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 226; Mineralogical Record (2000): 31(4): 345.
Iridium
Formula: (Ir,Os,Ru)
Description: Occurs with platinum in almost equal amounts plus traces of Pd & Rh.
Reference: Logan, Clarence August (1918), Platinum and allied metals in California: California Mining Bureau. Bulletin 85, 120 pp.: 29; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 41.
Iron
Formula: Fe
Reference: Goldstein, J.I. and Short, J.M. (1967) The iron meteorites, their thermal history and parent bodies. Geochimica et Cosmochimica Acta: 31: 1743; Goldstein, J.I. (1969) The classification of iron meteorites. In: P.M. Millman (Editor), Meteorite Research, D. Reidel, Dordecht-Holland: 736; Schaudy, R., Wasson, J.T., and Buchwald, V.F. (1972) The chemical classification of iron meteorites, VI. A reinvestigation of irons with Ge concentrations lower than 1 ppm. Icarus: 17: 174-192; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 58-59.
Iron var: Kamacite
Formula: (Fe,Ni)
Reference: Goldstein, J.I. and Short, J.M. (1967) The iron meteorites, their thermal history and parent bodies. Geochimica et Cosmochimica Acta: 31: 1743; Goldstein, J.I. (1969) The classification of iron meteorites. In: P.M. Millman (Editor), Meteorite Research, D. Reidel, Dordecht-Holland: 736; Schaudy, R., Wasson, J.T., and Buchwald, V.F. (1972) The chemical classification of iron meteorites, VI. A reinvestigation of irons with Ge concentrations lower than 1 ppm. Icarus: 17: 174-192; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 58-59.
'K Feldspar'
'K Feldspar var: Adularia'
Formula: KAlSi3O8
'Limonite'
Formula: (Fe,O,OH,H2O)
Localities: Reported from at least 6 localities in this region.
Magnesiochromite
Formula: MgCr2O4
Localities: Reported from at least 13 localities in this region.
Magnesite
Formula: MgCO3
Localities: Reported from at least 6 localities in this region.
Magnetite
Formula: Fe2+Fe3+2O4
Localities: Reported from at least 10 localities in this region.
Malachite
Formula: Cu2(CO3)(OH)2
Localities: Reported from at least 6 localities in this region.
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'
Margarite
Formula: CaAl2(Al2Si2O10)(OH)2
'Mariposite'
Formula: K(Al,Cr)2(Al,Si)4O10(OH)2
Massicot
Formula: PbO
Reference: Bradley, W.W. (1938), Thirty-fourth report of the State Mineralogist: California Division Mines Report 34: 194; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 257.
Molybdenite
Formula: MoS2
Muscovite
Formula: KAl2(AlSi3O10)(OH)2
Localities: Reported from at least 10 localities in this region.
Muscovite var: Phengite
Formula: KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2
Muscovite var: Sericite
Formula: KAl2(AlSi3O10)(OH)2
Localities:
Népouite
Formula: (Ni,Mg)3(Si2O5)(OH)4
Description: Occurs in laterite soils.
Reference: Clark, Wm. B. & D.W. Carlson (1956), Mines and mineral resources of El Dorado County, California: California Journal of Mines and Geology: 52(4): 387, 438; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 197; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 422.
Nontronite
Formula: Na0.3Fe2((Si,Al)4O10)(OH)2 · nH2O
Description: Occurs altered/altering to limonite.
Reference: Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 280.
Oldhamite
Formula: (Ca,Mg)S
Reference: Zolensky, M. & 21 others (2014) Mineralogy and petrography of C asteroid regolith: The Sutter's Mill CM meteorite. Meteoritics & Planetary Science 49(11): 1997-2016. (Nov 2014); Zhao, X., Lin,Y., Yin,Q.-Z., Zhang, J., Hao, J., Zolensky, M. & Jenniskens, P. (2014) Presolar grains in the CM2 chondrite Sutter's Mill. Meteoritics & Planetary Science 49(11): 2038-2046) (Nov 2014)
Opal
Formula: SiO2 · nH2O
Orthoclase
Formula: K(AlSi3O8)
Paragonite
Formula: NaAl2(AlSi3O10)(OH)2
Description: Occurs in graphitic metapelites.
Reference: Guidott, C.V., Post, J.L., and Cheney, J.T. (1979) Margarite pseudomorphs after chiastolite in the Georgetown area, California. American Mineralogist: 64: 728-732; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 431.
Pentlandite
Formula: (FexNiy)Σ9S8
Reference: Zolensky, M. & 21 others (2014) Mineralogy and petrography of C asteroid regolith: The Sutter's Mill CM meteorite. Meteoritics & Planetary Science 49(11): 1997-2016. (Nov 2014)
Petzite
Formula: Ag3AuTe2
Reference: Clark, Wm. B. & D.W. Carlson (1956), Mines and mineral resources of El Dorado County, California: California Journal of Mines and Geology: 52(4): 496; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 116; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 109.; Irelan, W. jr. (1893) Report of the state mineralogist, Issue 11
Platinum
Formula: Pt
Description: Occurs with iridium in almost equal amounts plus traces of Pd & Rh.
Reference: Logan, Clarence August (1918), Platinum and allied metals in California: California Mining Bureau. Bulletin 85, 120 pp.: 29; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 41.
Powellite
Formula: Ca(MoO4)
Prehnite
Formula: Ca2Al2Si3O10(OH)2
Description: Occurs in veinlets.
Reference: Pabst, Adolf (1936), Vesuvianite from Georgetown, California: American Mineralogist: 21: 2; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 386, 489; www.mineralsocal.org.
'Psilomelane'
Formula: Mn, O
Pyrite
Formula: FeS2
Localities: Reported from at least 54 localities in this region.
Pyrite var: Auriferous Pyrite
Formula: FeS2
Localities: Reported from at least 7 localities in this region.
Pyrolusite
Formula: Mn4+O2
Pyromorphite
Formula: Pb5(PO4)3Cl
Colour: Yellowish green
Description: Occurs as included matter in botryoidal chalcedony and as crystalline coatings.
Reference: Turner, Henry Ward (1902), Notes on unusual minerals from the Pacific states: American Journal of Science, 4th. Series: 13: 343-346; […(abstract): Mining and Scientific Press: 84: 296 (1902)]: 343; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 304.
Pyrophyllite
Formula: Al2Si4O10(OH)2
Reference: Dana 6: 22,82,1096.
'Pyroxene Group'
Pyrrhotite
Formula: Fe7S8
Quartz
Formula: SiO2
Localities: Reported from at least 440 localities in this region.
Quartz var: Amethyst
Formula: SiO2
Reference: Personal collection
Quartz var: Chalcedony
Formula: SiO2
Description: Botryoidal structures.
Reference: Turner, Henry Ward (1902), Notes on unusual minerals from the Pacific states: American Journal of Science, 4th. Series: 13: 343-346; […(abstract): Mining and Scientific Press: 84: 296 (1902)]: 343; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 304.
Quartz var: Citrine
Formula: SiO2
Reference: Personal collection
Quartz var: El Doradoite
Formula: SiO2
Colour: Blue
Description: Occurs in a pegmatite.
Reference: Watkins, S.L. (1917), El Doradoite: American Mineralogist: 2: 26; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 313.
Quartz var: Rock Crystal
Formula: SiO2
Quartz var: Rutilated Quartz
Formula: SiO2
Quartz var: Smoky Quartz
Formula: SiO2
Rectorite
Formula: (Na,Ca)Al4((Si,Al)8O20)(OH)4 · 2H2O
Reference: www.agry.purdue.edu/cjohnston/sourceclays/RAr-1.pdf.
Rhodonite
Formula: Mn2+SiO3
Riebeckite
Formula: ◻[Na2][Fe2+3Fe3+2]Si8O22(OH)2
Reference: Nash, J. Thomas (1988) Geology and geochemistry of gold deposits of the Big Canyon area, El Dorado County, California USGS Bull 1854.
Roscoelite (TL)
Formula: K(V3+,Al)2(AlSi3O10)(OH)2
Habit: radiating and foliated talc-like masses
Colour: Dark green; greenish grey in bulk, light greenish yellow in fragments
Description: Micaceous to ½ inch (1.25 cm) thick.
Reference: Blake, J. (1875) Roscoelite, a vanadium mica: Calif. Acad. Sci. Proc.: 6: 150; American Journal of Science, 3rd. series: 12: 31-32 (1876).; Genth, F.A. (1876) On some American vanadium minerals: American Journal of Science, 3rd. series: 12: 32-36; [Chem. News: 34: 78-79 (1876)]: 32.; Roscoe, H.E. (1876) IV. On two new vanadium minerals. Proceedings of the Royal Society of London: 25: 109-112.; Hillebrand, W.F, Turner, H.W., and Clarke, F.W. (1899) On roscoelite, with a note on its chemical composition. American Journal of Science, 4th. series: 7: 456.; Hillebrand, W.F. (1900) Mineralogical notes: SS Bulletin 167: 70.; www.eldoradolibrary.org
Rutile
Formula: TiO2
Scheelite
Formula: Ca(WO4)
Schreibersite
Formula: (Fe,Ni)3P
'Serpentine Subgroup'
Formula: D3[Si2O5](OH)4 D = Mg, Fe, Ni, Mn, Al, Zn
Localities: Reported from at least 21 localities in this region.
'Serpentine Subgroup var: Picrolite'
Formula: D3[Si2O5](OH)4 D= Mg, Fe, Ni, Mn, Al, Zn
Reference: Collected by Matthew Stanley in 2014
Siderite
Formula: FeCO3
Reference: Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 337.
'Silica'
Silver
Formula: Ag
'Soapstone'
Sphalerite
Formula: ZnS
Localities: Reported from at least 11 localities in this region.
Spinel
Formula: MgAl2O4
Reference: Zhao, X., Lin,Y., Yin,Q.-Z., Zhang, J., Hao, J., Zolensky, M. & Jenniskens, P. (2014) Presolar grains in the CM2 chondrite Sutter's Mill. Meteoritics & Planetary Science 49(11): 2038-2046) (Nov 2014)
Stibnite
Formula: Sb2S3
Strengite
Formula: FePO4 · 2H2O
Reference: www.mineralsocal.org
Stromeyerite ?
Formula: AgCuS
Description: Tentatively identified.
Reference: Logan, Clarence August (1938), Mineral resources of El Dorado County: California Journal of Mines and Geology, California Division Mines (Report 34): 34(3): 268; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 354.
Taenite
Formula: (Fe,Ni)
Reference: Goldstein, J.I. and Short, J.M. (1967) The iron meteorites, their thermal history and parent bodies. Geochimica et Cosmochimica Acta: 31: 1743; Goldstein, J.I. (1969) The classification of iron meteorites. In: P.M. Millman (Editor), Meteorite Research, D. Reidel, Dordecht-Holland: 736; Schaudy, R., Wasson, J.T., and Buchwald, V.F. (1972) The chemical classification of iron meteorites, VI. A reinvestigation of irons with Ge concentrations lower than 1 ppm. Icarus: 17: 174-192; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 58-59.
Talc
Formula: Mg3Si4O10(OH)2
Localities: Reported from at least 27 localities in this region.
Talc var: Steatite
Formula: Mg3(Si4O10)(OH)2
Tenorite ?
Formula: CuO
Description: Described as "gray oxide."
Reference: Aubury, Lewis E. (1902), The copper resources of California: California Mining Bureau Bulletin 23: 180; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 360.
'Tetrahedrite'
Formula: Cu6Cu4(X)2Sb4S13
Reference: Pemberton, H. Earl (1983), Minerals of California: 133.
Titanite
Formula: CaTi(SiO4)O
Tochilinite
Formula: Fe2+5-6(Mg,Fe2+)5S6(OH)10
Reference: Zolensky, M. & 21 others (2014) Mineralogy and petrography of C asteroid regolith: The Sutter's Mill CM meteorite. Meteoritics & Planetary Science 49(11): 1997-2016. (Nov 2014)
Topaz
Formula: Al2(SiO4)(F,OH)2
Reference: Ball, Sydney H. (1939), Gem stones: Minerals Yearbook, 1939: 1387; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 368.
'Tourmaline'
Formula: A(D3)G6(Si6O18)(BO3)3X3Z
Troilite
Formula: FeS
Reference: Zolensky, M. & 21 others (2014) Mineralogy and petrography of C asteroid regolith: The Sutter's Mill CM meteorite. Meteoritics & Planetary Science 49(11): 1997-2016. (Nov 2014)
Turquoise
Formula: Cu(Al,Fe3+)6(PO4)4(OH)8 · 4H2O
Reference: Mineralogical Research Company