Chalcopyrite << `kal` koh PY ryt >> is the most widespread copper ore and one of the chief sources of copper. It is a compound of copper, iron, and sulfur. The ore is a brassy yellow with a metallic luster. It looks like gold but is slightly harder and more brittle. When tarnished, much chalcopyrite displays changing colors like those of the rainbow. The ore has a rare crystal structure called tetragonal-scalenohedral—a shape like that of an eight-sided wedge. Chalcopyrite can be scratched with a steel knife. The resulting streak is greenish black. Major deposits of chalcopyrite occur in Canada, Japan, Spain, and the United States. The major U.S. deposits are in Arizona, Montana, Tennessee, and Utah. See also Copper.
