Sunnyside Mine (American Tunnel; Mogul Mine; Washington Mine; Belle Creole; Gold Prince; Brenneman Mine; Sunnyside Mine Group), Gladstone, Eureka District, San Juan Co., Colorado, USA
Latitude: 37°54'11"N
Longitude: 107°36'41"W
A gold-silver-lead-copper-zinc mine that worked veins associated with the Eureka graben. Started in the late 1880's and closed 1930. Reopened 1937 and closed 1938. Worked 1959 through 1985 (1960's - worked the Washington vein) via the American tunnel at Gladstone. On June 4th, 1978 (fortunately a Sunday) the bottom of Lake Emma collapsed into the upper mine workings sending a slurry of mud and debris through most of the workings. Production resumed after about 2 years of rehabilitation and the operation stumbled on through poor economic times until early in 1985. Worked 1985 until recently by Sunnyside Gold Corp., subsidiary of Echo Bay Mines, Ltd. Workings include the Terry shaft and the famous American Tunnel, often attributed to being its own mine. Produced over $150,000,000 in all metals mined. Past owners include: R.J. McNutt; M.M. Engleman& L.C. Thompson; L.C. Thompson & Frank Thompson; Judge John H. Terry (1900-1910); 2 sons & daughter of Judge Terry (1910-1917); United States Smelting & Refining Co. (1917- ); Standard Uranium (which formed Standard Metals Corp.)(lessee)(1959-1985).
Many old reports exist which claim rhodonite is common at this location. Modern methods of identification including X-ray diffraction of both massive and crystallized specimens show they are pyroxmangite.
Mineral List
40 entries listed. 33 valid minerals. 1 erroneous literature entry.
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References
Ref:(in part):
Rocks & Min.: 63: 366-384; 71:165-166; 75:306-307.
Economic Geology; 1977; v. 72; no. 7; p. 1285-1320
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