Chalcopyrite, like pyrite, is typically referred to as “fool’s gold”. Chalcopyrite has a similar appearance to gold and pyrite but is distinguished by its grey/green streak and hardness of 3.5-4, which can easily be scratched by a nail and pyrite cannot. Chalcopyrite is a sulphide bearing mineral and is one of the most important copper ores found in sulphide mineral deposits. It has a brassy iridescent yellow colour, metallic lustre and high specific gravity. Chalcopyrite is common in igneous rocks that crystallize from melts, and in metamorphic rocks like schists and gneiss.