Boulangerite

Tufts of boulangerite in the vugs in this dolomitic marble. Specimen comes from the Rogers Mine, a deposit first discovered in 1909 for its fluorite. Between 1910 and 1914 it was mined from an open pit. In 1914 a shaft was sunk, but the mine remained inactive until 1943 when Reliance Fluorspar Mining Syndicate Limited took over operations until 1951. This was the mine's most productive period and four shafts (37.5, 26.5, 36.5, and 73 m deep) were sunk. Some 39,000 tonnes of ore were produced during this period, making this the leading fluorite producer in the Madoc area. Some old buildings remain on the site. There are large dumps near the shafts.*

*https://www.mindat.org/loc-543.html