Quartz ''cast'' after Anhydrite

Item Description

These attractive and distinctive "casts" for years were labeled as Quartz after Baryte, but considering the fact that Baryte is chemically inert and nearly impossible to dissolve, it has been confirmed that they are "casts" of Quartz replacing Anhydrite. The first report I saw came from Dr. Virgil Lueth at New Mexico Tech who concluded that these and all San Juan Quartz epimorphs/perimorphs are in fact replacing Anhydrite. With that said, this specimen is a beautiful pseudomorph / cast consisting of hollow and blocky cavities of Quartz replacing the original mineral. 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, and show good gemminess The contrasting reddish iron-oxide inside the "cast" makes for a great touch as well, and confirms it's from the Silver Point Mine. This specimen was collected by noted Colorado collector and dealer, Benjy Kuehling in the 1980s. A wonderful specimen from a district that produced some of the most classic "casts" from all of Colorado.
From the collection of Armon McPherson, a retired physicist, now living in New Mexico. Armon received his PhD from North Carolina State University in 1985, and worked at the laser laboratory at the University of Illinois at Circle Center. In the summer of 1997, Armon moved to the Argonne National Laboratory where he worked at the Advanced Photon Source, then the world’s largest synchrotron facility dedicated as an x-ray source. In 2001, he was asked to join a team at Sandia National Laboratories in Albuquerque to conduct laser research for DARPA. Finally, staying within Sandia, he transferred to the Z Facility, the world’s most powerful x-ray facility. He retired in the spring of 2017. Armon's introduction to mineral collecting came in the 1980s during graduate school when he attended his first mineral show. He took up the hobby of faceting gems, and focused his early collection on gem crystals, and later transitioned into collecting non-gem species. We are proud to offer specimens from his worldwide mineral collection here for you.