Fluorite with Sphalerite and Chalcopyrite

Item Description

A wonderful older specimen from the famous Naica Mine featuring attractive, sharp, lustrous, rather gemmy, soft blue-purple colored cubes of Fluorite measuring up to 1.5 cm on edge, associated with cluster of black Sphalerite which have an epitaxial overgrowth of brassy metallic Chalcopyrite on matrix. I found a very nice "Spinel twin" of Sphalerite on the upper portion of the specimen, isolated and beautiful up close. The Fluorites appear to have to some small secondary tetrahexahedral faces, which is not commonly seen from this locality, though they could be octahedral faces. There is a bit of peripheral roughness, but the piece is largely in very good condition. Valued at $800 retail. From the collection of William ("Bill") (1927-2006) and Anne (1928-2021) Cook of Cleveland, Ohio (#3674), and accompanied by an old label from Gene Schlepp. This husband and wife duo were actively involved in the mineral world for many decades. Bill was a PhD geologist, and Anne was a mathematician, and they both were very serious mineral collectors. Bill served for many years as adjunct curator of mineralogy at the Cleveland Museum of Natural History, and Anne was inducted into the Micromounters' Hall of Fame on October 12, 2019. Both Bill and Anne, at various times, served as president both of the Mineralogical Society of Cleveland and of the Micromineral Society of the Cleveland Museum of Natural History, and Anne was inducted into the mi The rare barium lithium beryllium phosphate Wilancookite was named in their honor in 2015.