Malachite pseudomorph after Baryte

Item Description

It's fairly difficult to find specimens from this lesser-known copper deposit on the market these days. This particular specimen features a rarely seen phenomenon of Malachite pseudomorphing Baryte. This piece is a fairly rare, but showy pseudomorph from the Shangulowé Mine (originally labeled as coming from Musonoi, and "Mashamba", and one of them supposed the Malachite was replacing Torbernite originally), featuring sparkly Malachite crystals which have replaced thin Baryte blades. Seldom available material, mined decades ago circa 1970s.
From the collection of William ("Bill") (1927-2006) and Anne (1928-2021) Cook of Cleveland, Ohio (#9734) accompanied by an old Rocksmiths label and a label from the collection of Glenn and Kathleen Bolick. 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.