Mine detail: Bigger Mica Mine

Previously called 'Sweitzer Lode'

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Location

Lat / long:

39.56471, -105.21502

Resource(B)

Primary:	Feldspar, Mica, Beryllium
Tertiary:	Uranium, Bismuth, Niobium (Columbium), REE, Tin, Tantalum
Ore:	Beryl, Bismuthinite, Bismutite, Cassiterite, Columbite, Microcline, Monazite, Muscovite
Gangue:	Albite, Quartz, Tourmaline
Orebody form:	TABULAR
Other material:	Uraninite
Discovery year:	1884

Production

Operation type:	Unknown
Production size:	Small
Development status:	Past Producer
First production started:	1884
Last production ended:	1935

Geology

Host rock:	Gneissic Quartz Monzonite And Granodiorite;Biotite Gneiss
Host type:	Diorite
Associated rock:	Gneissis Quartz Monzonite And Granodiorite;Coarse-Grained Pegmatite
Associated type:	Diorite,Pegmatite
Structure:	Front Range Uplift, Denver Basin, Floyd Hill Fault Zone
Tectonic:	Central Cordillera (Southern Rocky Mtns)

References

MRDS	D010204
DEP	10013744
Reference	{Deposit:: BRYANT, BRUCE, AND OTHERS, 1973, GEOLOGIC MAP OF THE INDIAN HILLS QUADRANGLE, JEFFERSON COUNTY, COLORADO: USGS MAP GQ-1073}{Deposit:: HANLEY, J.B., AND OTHERS, 1950, PEGMATITE INVESTIGATIONS IN COLORADO, WYOMING, AND UTAH, 1942-44: USGS PROF. PAPER 227, P. 82-84}{Deposit:: MEEVES, H.C., AND OTHERS, 1966, RECONNAISSANCE OF BERYLLIUM-BEARING PEGMATITE DEPOSITS IN SIX WESTERN STATES: USBM IC-8298, P. 27.}
Reporter	Schwochow, Stephen D.