CHEMISTRY CuFe2S3 copper iron sulfate
CRYSTALLOGRAPHY Orthorhombic
CRYSTAL GROWTH AND HABITS Cubanite crystals are usually elongated and tabular, normally thick and striated. Cubanite is also commonly massive. Twinning is common, typically in pairs but also as a set of four and even sixling twins.
COLOR AND OTHER OPTICAL PROPERTIES Brassy to bronze yellow
HARDNESS 3.5
SPECIFIC GRAVITY 4.03 - 4.18
LUSTER Bright yellow metallic, like pyrite
STREAK Dark gray to black
BREAKABILITY Brittle
OTHER Cubanite is strongly magnetic
OCCURRENCE Cubanite is found in high temperature hydrothermal veins. It often occurs as aligned intergrowths with chalcopyrite.
ASSOCIATED MINERALS chalcopyrite, pyrite, pyrrhotite, sphalerite
NAME Named from its occurrence in Cuba