Silver, Arsenides

Rich silver specimen from the Siscoe O'Brien Mine. This slab displays both dendritic silver and carbonate vein infilling. Excellent example of the kind of material that comes out of the Gowganda area of Ontario!

Also known as the Miller Lake O'Brien Mine.. It is a silver-cobalt mine discovered in 1908, acquired by the Miller Lake Co.in 1909 and then Siscoe Mines Limited in 1945. The workings had reached a depth of 1300 feet by 1962 (as reported in "Precambrian" magazine June 1962 issue).
Total production up to 1965 was 36,830,000 oz. Ag and 786,000lbs Co.* It was a rich mine!

*https://www.mindat.org/loc-23120.html