Silver

This specimen comprises both halves of a nodule of ore rock, precisely cut down the centre, offering a clear view of the material as it appears when detected by metal detectors in the Cobalt area. It reveals a thick vein of silver intermingled with safflorite and other arsenides within a dolomitic host rock. The specimen originates from the Hargrave Mine, a relatively rare locality discovered in 1905 and operated by Hargrave Silver Mines Ltd. from 1908 to 1921. The deposit was accessed through two shafts, the deepest reaching 550 feet. By 1920, the mine had produced approximately 500,000 ounces of silver and 6,400 pounds of cobalt, with no recorded mining activity after 1928.*

*https://www.mindat.org/loc-11743.html