Bornite
Image: Islam90 (CC BY-SA 4.0)
Mineral NameBornite
Chemical FormulaCu₅FeS₄
Mohs Hardness3
Crystal Systemtetragonal
Lustermetallic
Streak Colorgrayish black
Cleavageindistinct on {111}
Fractureconchoidal to uneven
Specific Gravity4.9
Colorscopper-red, brownish bronze, iridescent purple, blue, red
Transparencyopaque
Type LocalityButte, Montana, USA
Mineral GroupSulfides
Usescopper ore
Associated Mineralschalcopyrite, pyrite, chalcocite, covellite
Raritycommon
Description
The image displays a microscopic view of a polished Bornite surface, showing a predominant brownish-orange color with some darker, irregular patches and numerous fine scratches, characteristic of a metallic mineral.
Geological Context
Bornite typically forms in hydrothermal veins, porphyry copper deposits, and contact metamorphic zones, often associated with other copper sulfides. It is a primary ore mineral in many copper deposits.
