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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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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

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

Rock Types Recorded

Note: 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)Si8O22OH2
Reference: Klein, C. (1969) Two-amphibole assemblages in the system actinolite-hornblende-glaucophane. American Mineralogist: 54: 212-237; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 396.
Albite
Formula: Na(AlSi3O8)
Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.; Nash, J. Thomas (1988) Geology and geochemistry of gold deposits of the Big Canyon area, El Dorado County, California USGS Bull 1854
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.
Ankerite
Formula: Ca(Fe2+,Mg)(CO3)2
Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
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
Reference: Aubury, Lewis E. (1908), The copper resources of California: California Mining Bureau. Bulletin 50: 213; 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: 93; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 224. USGS Bull 1182E.
Bornite
Formula: Cu5FeS4
Localities: Reported from at least 11 localities in this region.
Description: Occurs as massive material with molybdenite in a coarse pegmatite.
Reference: Aubury, Lewis E. (1902), The copper resources of California: California Mining Bureau Bulletin 23: 180; 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: 110, 129, 131, 175. USGS Bull 1182E
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
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.
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 22 localities in this region.
Description: Occurs as good crystals.
Reference: Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 117. USGS Bull 1182E.
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
Reference: Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 129.
Chalcopyrite
Formula: CuFeS2
Localities: Reported from at least 31 localities in this region.
Reference: Dana 6:82.
'Chlorite Group'
Localities: Reported from at least 10 localities in this region.
Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Chromite
Formula: Fe2+Cr3+2O4
Localities: Reported from at least 71 localities in this region.
Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Chrysotile
Formula: Mg3(Si2O5)(OH)4
Description: Fibrous; occurs in veins.
Reference: Logan, Clarence August (1926), El Dorado, Shasta and Trinity Counties: California Mining Bureau. Report 22: 404; Logan, Clarence August (1938), Mineral resources of El Dorado County: California Journal of Mines and Geology, California Division Mines (Report 34): 34(3): 207, 261; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 422.
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.
Reference: Mineralogical Record:31(4):345
Clinochlore var. Chromium-bearing Clinochlore
Formula: Mg5(Al,Cr)2Si3O10(OH)8
Localities: Reported from at least 11 localities in this region.
Reference: Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 136.
Clinochlore var. Pennine
Formula: Mg5Al(AlSi3O10)(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.
Clinochlore var. Ripidolite
Formula: (Mg,Fe,Al)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; http://cms.lanl.gov/chem.htm.
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
Reference: Dana 6: 22,82,1096.
'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
Description: 40 to 50 stones found before 1867, some 1 to 1½ carets.
Reference: Silliman, Benjamin, Jr. (1867c), On new localities of diamonds in California: American Journal of Science, 2nd. series: 44: 119; Kunz, George Frederick (1905a), Gems, jewelers’ materials, and ornamental stones of California: California Division Mines Bulletin 37, 171 pp.: 43; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 171.
Diopside
Formula: CaMgSi2O6
Localities: Reported from at least 6 localities in this region.
Colour: White
Description: Massive material and lath-like crystals to 7 mm wide; resembles vesuvianite.
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.; Len Pisciotta (2019) White grossular from near the Stifle claim, Georgetown, El Dorado County, California. Mineralogical Record 50:713-717
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: Mg2Si2O6
Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Epidote
Formula: {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Localities: Reported from at least 10 localities in this region.
Description: Occurs as large crystals coated by axinite in a coarse vein.
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: 91, 175. USGS Bull 1182E
'Fayalite-Forsterite Series'
Localities: Reported from at least 8 localities in this region.
Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
'Feldspar Group'
Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
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.
Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
'Garnet Group'
Formula: X3Z2(SiO4)3
Localities: Reported from at least 8 localities in this region.
Reference: Kunz,1892. Gems & Precious Stones of N. America
'Garnierite'
Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Gold
Formula: Au
Localities: Reported from at least 623 localities in this region.
Description: Crystallized Au present.
Reference: www.mineralsocal.org; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10086458.
Graphite
Formula: C
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.
Grossular
Formula: Ca3Al2(SiO4)3
Description: Occurs as large crystals.
Reference: 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: 193. USGS Bull 1182E.
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
Description: A float specimen was found in 1854.
Reference: Blake, Wm. P. (1857), Note on the occurrence of telluret of silver in California: California Academy of (Natural) Sciences Proceedings: 1: 270; Blake, Wm. P. (1858), Report of a geological reconnaissance in California 370 pp., New York: 302, 303; Hanks, Henry Garber (1884), Fourth report of the State Mineralogist: California Mining Bureau. Report 4, 410 pp.: 229.
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'
Colour: Black
Description: Occurs as large cleavage masses.
Reference: Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 65. USGS Bull 1182E.
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'
Colour: Colorless
Description: Occurs as crystals.
Reference: Rogers, Austin Flint (1912), Notes on rare minerals from California: Columbia University, School of Mines Quarterly: 33: 376; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 184.
'K Feldspar var. Adularia'
Formula: KAlSi3O8
Colour: Colorless
Description: Occurs as crystals.
Reference: Rogers, Austin Flint (1912), Notes on rare minerals from California: Columbia University, School of Mines Quarterly: 33: 376; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 184.
'Limonite'
Formula: (Fe,O,OH,H2O)
Localities: Reported from at least 6 localities in this region.
Reference: USGS Bull 1182E
Magnesiochromite
Formula: MgCr2O4
Localities: Reported from at least 13 localities in this region.
Reference: Cater, F.W., Jr., G.A. Rynearson & D.H. Dow (1951), Chromite deposits of El Dorado County, California: California Division Mines Bulletin 134, part III, Chapter 4: 128 (3rd. paragraph), 164, Pl. 8; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 156 (map 4-7).
Magnesite
Formula: MgCO3
Localities: Reported from at least 6 localities in this region.
Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Magnetite
Formula: Fe2+Fe3+2O4
Localities: Reported from at least 10 localities in this region.
Description: Occurs as octahedral crystals to 2.5 cm in Chlorite schist.
Reference: Pemberton, H. Earl (1983), Minerals of California: 148.
Malachite
Formula: Cu2(CO3)(OH)2
Localities: Reported from at least 6 localities in this region.
Reference: Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 224. USGS Bull 1182E.
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.
Margarite
Formula: CaAl2(Al2Si2O10)(OH)2
Reference: AmMin 64:728
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
Description: Occurs with massive bornite as foliated plates and crystals to 6 cm diameter in a coarse pegmatite.
Reference: Dana, Edward Salisbury (1892), System of mineralogy, 6th. ed., 1134 pp., Wiley & Sons, New York: 22, 82, 1096; 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): 274; Aubury, Lewis E. (1902), The copper resources of California: California Mining Bureau Bulletin 23: 180; 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: 110, 131, 175, 268. USGS Bull 1182E.
Muscovite
Formula: KAl2(AlSi3O10)(OH)2
Localities: Reported from at least 10 localities in this region.
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.
Muscovite var. Mariposite
Formula: K(Al,Cr)2(Al,Si)4O10(OH)2
Description: Occurs as a gangue mineral in Au mines.
Reference: Clark, Wm. B. & D.W. Carlson (1956), Mines and mineral resources of El Dorado County, California: California Journal of Mines and Geology: 52: 401; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 425.
Muscovite var. Phengite
Formula: KAl1.5(Mg,Fe)0.5(Al0.5Si3.5O10)(OH)2
Description: Occurs as a gangue mineral in Au mines.
Reference: Clark, Wm. B. & D.W. Carlson (1956), Mines and mineral resources of El Dorado County, California: California Journal of Mines and Geology: 52: 401; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 425.
Muscovite var. Sericite
Formula: KAl2(AlSi3O10)(OH)2
Localities:
Description: Occurs as sericite schist.
Reference: USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10095088.
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 limon