Bornite on Chalcopyrite with Quartz and Pyrite Specimen - Brazil

Bornite on Chalcopyrite with Quartz and Pyrite Specimen – Brazil (Minas Gerais, Iron Quadrangle)

Specimen weight: 264g

Vibrant iridescent bornite (Cu₅FeS₄) exhibiting electric blue to violet tarnish, overgrowing chalcopyrite crystals on a quartz matrix with micro-pyrite inclusions. The "peacock ore" effect arises from surface oxidation layers, while quartz ranges from translucent grey to milky white. Pyrite micro-crystals add metallic contrast. Formed in hydrothermal sulfide veins of Precambrian banded iron formations. Noted for bold color interplay and matrix integrity – specimens >8 cm command premium value due to crystallographic complexity.

Measurement scale in centimeters (cm).