Mineral description : Chalcopyrite

Chalcopyrite, unknown locality but probably Skellefteå mining field.
Chalcopyrite from Alnö area.
All crystals damaged, but one face remains showing striation.
Chalcopyrite from Alnö area.
A few crystals, one big (6mm) showing heavy twinning.

Mineral class Sulphides : Chalcopyrite - Bornite broup
Chemical formula CuFeS2
Crystal system Tetragonal.
Habitus Small flat tetraedic crystals, often twinned and with striations on the crystal faces. More often as massive or grainy aggregates.
Cleavage Poor, uneven to conchoidal cleavage.
Hardness 3.5-4
Density 4.3-4.4
Color Yellow, deeper than pyrite. Often with irisdescent tarnish.
Streak Greenish black.
Luster Metallic, opaque.
Description One of the most important ores of copper.
Occurance Forms with sulphide ores, in hydrothermal veins, in magmatic rocks. More rarely in pegmatites or metamorphic rocks.
Associates Pyrrhotite, quartz, calcite, pyrite, sphalerite, galena.
Notes Soluble in nitric acid. Colors a flame green.
Locations A very common mineral with a number of mines in Sweden, primarily in Bergslagen and Skellefteå field. Crystals are more rare but can also be found.
  • Tabergsgruvan, Nordmarken, Värmland. Up to 5mm crystals in calcite filled cavities.
  • Insjö mine, Dalarna. Quite big but rare crystals in chlorite.
  • Vassviks mine, Ånimskog, Dalsland. Small crystals up to 2mm with calcite, flourite and galena in quartz vugs.
  • Knollegruvan, Ånimskog, Dalsland. Up to 1 cm crystals in quartz with dolomite, fluorite and siderite.
  • Åtvidaberg field, Östergötland. Up to 1 cm crystals in quartz have been found in several mines, primarilly Malmviksgruvan.
  • Gladhammar mines, Småland. Rich findings of crystals up to 1 cm with quartz in cavities.
  • Alnö area, Sunsvall. As small crystals in cavities in calcite.

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Last changed : 1998-04-24