| Numerous fissure veins and fracture planes were present that contained brittle arsenical copper and chalcocite. |
| Cuprite occurred along with chalcocite as inclusions in small calcite crystals. |
| We have seen sooty black material associated with native copper from the Eagle mine that is almost certainly chalcocite. |
| Spiroff reports cleavable masses of black calcite, with the color probably due to inclusions of chalcocite or tenorite. |
| Microcrystals of azurite and goethite and a small number of microcrystals of chalcocite were also recovered. |
| Some specimen labels state that this coating is chalcocite, but, to the best of my knowledge, the identity has not been established by analysis. |
