Arsenopyrite

Item Description

Please note: When these specimens first came out, they were originally identified as Löllingite, but subsequent analysis has shown that all of them are Arsenopyrite. As a matter of fact, Löllingite is not even listed as a reported species from the San José Mine. With that said, it has happened many times where Arsenopyrite has been confused for Löllingite due to their similarities in chemistry, but I will say that this piece is definitively Arsenopyrite, and a beautiful one at that. It's one of the most attractive examples of the species that we've ever had to offer from this mine. Several sharp, lustrous, well-formed, prismatic crystals of a silvery metallic hue are intergrown to form a beautiful "cockscomb"-esque or "fan"-like group, free of matrix. The piece is in excellent condition, and the crystals are terminated with no major damage I can see, only a few little rough spots. Even though this is a smaller specimen, it's one of the showiest pieces of Arsenopyrite I can remember seeing from the locality. A really choice small miniature sized piece from this prestigious locale.
This piece was mined around 1980 and is a great example of this old material from one of the most famous mines in the Bolivian tin belt
From the collection of Gary and Terry Butts of Livermore, Colorado. This husband and wife collecting duo were childhood sweethearts, and have been together since they began dating as teenagers growing up in East Des Moines, Iowa in the 1950s. Both of them had an early interest in the hobby thanks to the fact that Terry's parents had a keen interest in lapidary, which sparked an interest in rocks for both of them. Gary and Terry were featured in an article in the Des Moines Register on Feb 4, 1962 (see photo in this listing) highlighting their interest and prowess in the hobby as youngsters. Gary traveled to various localities around the US as a teenager with his father (who worked in the tin industry), to personally collect specimens. He then attended the School of Mines in Golden, Colorado and graduated in 1967 with a degree in extractive metallurgical engineering. We went to work for Duval Corp at the Esperanza Mine south of Tucson, Arizona and then work for Cyprus Mines, Hazen Research, Pincock, Allen & Holt and the Colorado School of Mines Research Institute. His final job was in the mineral and environmental division of Intertek Testing Services of London, which owned the Canadian mineral testing company, Bonder Clegg. Gary's various jobs allowed him to travel the world and build his collection by buying a lot of specimens in person when they were coming out of the ground. Additionally, Terry's uncle was a miner in Creede, Colorado and later owned a rock shop which supplied Gary with specimens from the area. The specimens in this auction represent what Gary and Terry considered the "cream of the crop" of their collection.