Tennantite Subgroup pseudomorph after Enargite with Baryte

Item Description

Here we have a hefty, good-sized display piece of these classic and fairly rare pseudomorphs from Peru. The specimen features bronze-colored Tennantite (the specific species isn't known, so it should be labeled as Tennantite Subgroup) which have replaced / pseudomorph crystals of Enargite associated with bladed white Baryte crystals (several of which are unfortunately broken) free of matrix. Individual crystals are hard to isolate, but the largest prism I could measure was 1.8 cm long. There are some contacts, but overall the piece is in good condition, and is quite showy. A very nice old-time example of these now seldom seen specimens from a few decades ago.
From the collection of William ("Bill") (1927-2006) and Anne (1928-2021) Cook of Cleveland, Ohio (#12877). 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. The rare barium lithium beryllium phosphate Wilancookite was named in their honor in 2015.