- Cuprous sulfide, an ore of copper, usually occurring as black, fine-grained masses.
More example sentences
- Chemical formula: Cu2S
- Numerous fissure veins and fracture planes were present that contained brittle arsenical copper and chalcocite.
- We have seen sooty black material associated with native copper from the Eagle mine that is almost certainly chalcocite.
- At the Kingston mine, calcite occurred as thin massive veins cutting the lode and as modified rhombohedral crystals to 7 mm with inclusions of cuprite and chalcocite.