Chalcopyrite ( KAL-kə-PY-ryte, -koh-) is a copper iron sulfide mineral and the most abundant copper ore mineral. It has the chemical formula CuFeS2 and crystallizes in the tetragonal system. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green-tinged black.
Chalcopyrite
Microscopic picture of chalcopyrite
Brass-yellow chalcopyrite crystals below large striated pyrite cubes
Copper-zinc ore sample from a VMS deposit at Potter Mine in Timmins, Ontario, Canada. The brassy-yellow mineral is chalcopyrite- the primary ore mineral at this mine.
Copper is a chemical element; it has symbol Cu and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement.
Copper
A copper disc (99.95% pure) made by continuous casting; etched to reveal crystallites
Unoxidized copper wire (left) and oxidized copper wire (right)
The East Tower of the Royal Observatory, Edinburgh, showing the contrast between the refurbished copper installed in 2010 and the green color of the original 1894 copper