Alum (Potassium Alum) (synthetic)

Item Description

Here we have an attractive specimen of synthetic / man made alum. For the sake of clarity, this piece is only labeled as "alum", but that typically refers to potassium alum which is chemically KAl(SO4)·12 H2O. Other less common alum compounds are sodium alum and ammonium alum, but I'm 99% certain this is potassium alum. This material is found in nature in the form of Alunite, though the chemical compostion is slightly different than synthetic potassium alum. Some of you might have seen alum in the baking/canning aisle at the grocery store, where it's used in pickling to keep vegetables crisp in brine. The substance is typically white/colorless, but this one is oddly blue, clearly there was some kind of chromophore added to the mix when these crystals were grown, but it's hard to say specifically what it could be. The entire display side of the piece is covered with sharp, lustrous, gemmy/translucent octahedral crystals of alum measuring up to 1.3 cm across. No major damage and very attractive in person. A really cool synthetic specimen from the collection of William ("Bill") (1927-2006) and Anne (1928-2021) Cook of Cleveland, Ohio (#7728). 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.