Mineralpedia Details for Chalcocite
Chalcocite
- Formula
- Cu2S
- Crystal System
- Monoclinic
- Crystal Habit
- Massive, Granular, Euhedral Crystals
- Cleavage
- Indistinct, None, None
- Luster
- Metallic
- Color
- blue black, gray, black, black gray, steel gray
- Streak
- grayish black
- Class
- Monoclinic - Prismatic
- Fracture
- Conchoidal
- Hardness
- 2.5-3
- WebMineral
- View Chalcocite
- Mindat
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Chalcocite from Geevor mine, Pendeen, St Just dist., Cornwall, England
Small specimen with sharp, textbook, steel grey, pseudo-hexagonal Chalcocite crystals to 5mm. Historically significant mine known for its Chalcocite crystals as part of the Levant mine.
Chalcocite from Mountain Consolidated mine, Butte, Silver Bow Co., Montana, United States
- Special Info
- Phillips Collection
Steel grey free-standing swords of Chalcocite to 9mm generally averaing 5mm. There is a slight iridescence of a blue tone.
Chalcocite from Belmont mine, Butte, Silver Bow Co., Montana, United States
Excellent group of dull blackened Chalcocite crystals, the largest to 1cm.
Chalcocite from Flambeau mine, Ladysmith, Rusk Co., Wisconsin, United States
Brassy to purple iridescent crude to nice Chalcocite crystals to 1cm in a cluster. More specifically the specimen came out of the Lucky Friday Pocket (1000 ft.) level.
Chalcocite from Dzhezkazgan mine, Karagandy, Kazakhstan
Nice pseudohexagonal cyclic twinned Chalcosite crystals to 8mm with a bluish iridescnce caused by probably Bornite.
Chalcocite from Bisbee, Cochise Co., Arizona, United States
Excellent little, well-formed cyclic twinned Chalcocite crystals to 2mm on the side of mostly Bornite matrix.
Chalcocite from Steward mine, Butte dist., Silver Bow Co., Montana, United States
Twinned Chalcocite crystals to 3mm.
Chalcocite from Tsumeb mine, Tsumeb, Namibia
Elongated needle Chalcocite crystals to 8mm, some look to be spinel twins with discoidal Siderite.
Verified by EDS, this specimen of Chalcocite contains weird elongated, acicular crystals to 8mm.
Chalcocite from Tincroft mine, Redruth dist., Cornwall, England
Superb specimen loaded with countless pseudo-hexagonal plates formed by twinning of monoclinic Chalcocite. Crystals such as these from Cornwall are highly sought after and valuable. The crystals are all nearly the same size from 4 to 7mm across and all nearly in perfect condition with good shiny luster. The Tincroft is another classic Cornish locality which mined early, shallow tin before converting to mining copper in the enriched zoned where this Chalcocite was likely found.
Chalcocite from Chino mine, Grant Co., New Mexico, United States
Steely grey, very homogenous mass of pure Chalcocite on phorphyry matrix.
Chalcocite from Nacimiento mine, San Pablo, Sandoval Co., New Mexico, United States
Black to grey massive Chalcocite which has replaced most of petrified wood.
