black ore
black ore
Partly decomposed pyrite containing copper
In uranium mining, the term may mean ore containing a high proportion of pitchblende, uraninite, coffinite, or vanoxite.
Cumb. A variety of hematite in hard pieces, some kidney shaped, reaching the size of one's hand, in a moderately soft, dark-red, brown, or nearly black mass of smit clay and manganese oxide, the whole having a most confused appearance.