We have had a couple of these Arizona classics in the auctions lately, from completely different collections. They have always been favorites - robins-egg blue chrysocolla covered with a coating of sugary, sparkly quartz. And, they have never been available in quantity, so they get good money on the market. This is a large and very impressive one! The label that came with it is from dealer Claude Humber, and indicates that he collected it himself at the mine in 1975.