Bornite Apr 2026

: Orthorhombic at normal temperatures, though it often retains its high-temperature isometric (cubic) form, making well-formed crystals rare.

Cu5FeS4cap C u sub 5 cap F e cap S sub 4 ) is a copper iron sulfide mineral famously known as due to its spectacular iridescent tarnish. While fresh surfaces appear metallic copper-red to bronze-brown, exposure to air causes rapid oxidation, resulting in a vibrant, rainbow-like shimmer of purples, blues, and golds. Key Mineralogical Features bornite

: Valued for its high copper content and ease of reduction to metallic copper. : Orthorhombic at normal temperatures, though it often

: Primarily found in hydrothermal copper veins , porphyry copper deposits, and contact metamorphic rocks. Economic and Scientific Importance : Orthorhombic at normal temperatures