Ferberite (twin)

Item Description

This is a rather hefty (971 grams = 2 pounds, 2 ounces) and robust example of the classic twinned Ferberites from the renowned Tasna Mine in Bolivia. Without a doubt, some of the finest Ferberite crystals in the world have come from this giant bismuth mine, and the twins are the best examples of the material in the world. This piece shows the classic, "butterfly" twinning habit along the a (100) face of the crystals creating a fine sharp, blocky, jet-black twin, free of matrix. There are some damaged spots, so it's not pristine, but it's larger than most you'll see from the locality. It's very hard to get fine quality, undamaged twins of Ferberite from any locality, as Tasna is no exception. Twinned Ferberite crystals from this mine have becoming increasingly difficult for us to obtain, as the miners do not take care of the crystals, so they're almost always dinged or cleaved. In addition, the price of tungsten can cause superb twinned crystals to be thrown into the crusher and destroyed for the mere value of their ore.
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.