Calcite pseudomorph after Alabandite (RARE) (ex Bill and Anne Cook Collection)

Item Description

The famous Uchucchacua Mine in Peru has produced some excellent and eye-catching mineral specimens for decades. In recent years, this mine produced some world-class Alabandite crystals, but this piece is even more unique/interesting as it's actually an incredibly hard to find pseudomorph of Calcite replacing Alabandite! You can see there are several octahedral crystals of Alabandite measuring up to 1.1 cm, but you can clearly see there are beautiful pink aggregates of pink Calcite (manganese-bearing) along with a thin layer that is actually forming pseudomorphs after Alabandite. You might think this thin layer is just a coating, but there are a couple broken Alabandite crystals on the piece which actually reveal they are partially hollow inside and contain a small amount of the pink Calcite, so this is truly a replacement, and to the best of my knowledge, the only place in this world where this specific pseudomorph has been reported. The piece comes with a label from noted Peruvian mineral expert, Jaroslav Hyrsl, who presumably acquired the specimen directly at the mine. If you collect pseudomorphs, unique minerals of specimens from Peru, do NOT pass up the opportunity to get your hands on this piece, as it may be the ONLY one you'll see from the locality. Valued at $1,000-1,500 for the uniqueness of the specimen. From the collection of William ("Bill") (1927-2006) and Anne (1928-2021) Cook of Cleveland, Ohio. 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.