CHALCOCITE SPECIMENS
Chalcocite is a secondary copper sulfide mineral that forms in or near the oxidized zone of copper sulfide deposits. It typically has a metallic luster and can display a blue-black, gray, black, black gray, or steel gray coloration. It was named chalcosine in 1832 by François Sulpice Beudant from the Greek word "chalkos (khalkos)", meaning "copper". It was later renamed "chalcocite" 1868 by James D. Dana and George J. Brush.