An underground copper mine consisting of three shafts located near Mass City, MI. The Knowlton Mining Co. was organized in 1860 but exploration work started in 1853. The mine officially closed in 1867, but work continued on tribute until 1885. The mine produced approx. 992,000 lbs. of refined copper. Minerals that can be found include copper, silver, datolite, and other micro minerals.
Mineral List
3 entries listed. 3 valid minerals.
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References
Butler, B.S., and Burbank, W.S., 1929, The Copper Deposits of Michigan. U.S. Geological Survey. Professional Paper 144. 238 pp.
The Copper Country Rock & Mineral Club, 2001, Red Gold and Tarnished Silver, 2nd Ed., 44 pp.
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