Quartz "cast" after Anhydrite (ex Kay Robertson Collection)

Item Description

These specimens have been labeled as being Quartz after Barite, but given the fact that Barite is chemically inert and nearly impossible to dissolve, it is most likely that these pseudomorphs / epimorphs / perimorphs / "casts" are actually Quartz replacing Anhydrite. It has been reported that Dr. Virgil Lueth or New Mexico Tech concludes from studies (as-yet unpublished paper 4/2011) that these and all San Juan Quartz epimorphs apparently after Barite are in fact after Anhydrite. With that said, this specimen is a beautiful pseudomorph / cast consisting of a blocky crystal of what was once Anhydrite now completely replaced by sharp, lustrous Quartz crystals. The most attractive aspect of this specimen is the fact that the Quartz crystals are not microscopic or massive, but many of them are easily visible with the naked eye. This specimen was collected by noted Colorado collector and dealer, Benjy Kuehling. A wonderful specimen from a district that produced some of the most classic "casts" from all of Colorado. Ex Kay Robertson Collection (#2859). Kay is a prominent California collector, who specialized in European classics (see the article in the March-April, 2007 Mineralogical Record and the 50+ page article in the German Magazine "Mineralien Welt" November-December 2017).