| Webster's Online Dictionary |
| Expressions | Domain | Definition | |
| Black ore | Mining | A. Eng. Partly decomposed pyrite containing copper b. In uranium mining, the term may mean ore containing a high proportion of pitchblende, uraninite, coffinite, or vanoxite.c. 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 almost confused appearance. (references) | |
Source: compiled by the editor from various references; see credits. | Top | ||
