Chalcocite is a silver coloured mineral specimen with a metallic lustre and in the case of these pieces, a crystalline massive form. It is a copper sulphide mineral, making it a major source for copper ore, with the name actually being derived from the Greek word 'khalkos', meaning copper. Easily recognisable by its metallic appearance, it is actually quite soft,coming in at 2 to 3 on the Mohs scale of hardness index, meaning it can be scratched with just your finger nail. Chalcocite crystals tend to have an orthorhombic habit, but due to these specimens being a massive form, the crystals are too fine to see with out the aid of magnification. The mineral has been mined for centuries due to the fact that it is one of the best copper ores, with upto 80% of the material being able to be extracted as copper. Our pieces come from the U.S.A and exhibit text book details expected from chalcocite, available in a range of sizes, the pieces will come supplied in a card tray with an information label.