Algom Nordic Mine, Elliot Lake, Ontario, Canada
Rounded black pitchy grains scattered in crystalline calcite matrix, with chalcopyrite. When we first got this material in 1959 it was labeled "Thucholite", but was found to be uraninite with carbonaceous matter.
I have a few more, mostly smaller, specimens of this material, please email me for a quote if interested.
6x7x4.5cm Weight 196grams