Quartz ''cast'' after Fluorite

Item Description

The Idarado Mine in southwestern Colorado is one of the most famous ore localities in the state. It's one of the signature mines in the San Juan Mountains. This important base metal and gold producer gets is name from the combination of the Idaho based Sunshine Mining Company and Newmont Mining in Colorado (IDA-ho + coloRADO = IDARADO) but actual specimens of Gold are quite rare to find. This piece is rare for the locality, and features sugary white Quartz which has replaced cubic Fluorite, creating a beautiful pseudomorph/"cast". The piece is nearly a complete "floater", as it's crystallized all over, but there are a few thin edges where points of attachment can be seen on the periphery. While Quartz replacing Fluorite is not unheard of from various localities in the San Juan Mountains, I have seen very few of them from the Idarado Mine.
From the collection of Colorado mining legend, Dave Bergman. Dave actually self-collected this specimen while he worked at the Idarado Mine in the 1960s. Dave is now retired from mining, but was formerly the foreman and primary person in charge of recovering specimens at the famous Sweet Home Mine near Alma, Colorado during the late 1970s, and the maternal grandfather of Brian Kosnar. See Dave's photo mining at the Sweet Home on page 58 of Peter Bancroft's book "Gem and Crystal Treasures".​