Chrysocolla is a basic copper silicate made up of approximately 45% copper oxide (CuO) and 34% silica (SiO2). Chrycolla has a secondary origin, which means it is a metamorphic rock; one of those rocks which has changed its composition as a gesult of geological activity.
Chrysocolla is typically found as glassy botryoidal (a shape which resembles a bunch of grapes) or as rounded masses. The name is very old, being first used in 315 B.C. by Theophrastus, a student of Aristotle. It is derived from the Greek chrysos, meaning "gold," and kolla, meaning "glue," in allusion to the name of the material used to solder gold.
Chrysocolla has a distinctive light blue-green colour which resembles turquoise, although turquoise is a much harder mineral (hardness 6). True chrysocolla, free of quartz, is fragile and likely to crack as it loses water in dry cabinet environments. Chrysocolla-impregnated chalcedony, which has the quartz hardness of 7, is used in jewelry and as an ornamental stone.
Chrysocolla can be found in association with other copper minerals. The main sources are Israel, the Democratic Republic of Congo, Chile, Cornwall in England, and Arizona, Utah, New Mexico and Pennsylvania in the United States.
