Gismondine Subgroup (rare historic specimen) (Mined: 1878)

Item Description

An important and extremely rare locality specimen of the Gismondine Subgroup from Břidličný vrch (formerly called Schieferberg) which was first mentioned in writing in 1823. The locality lies right next to the Labe (Elbe) River about 10 km south of Ústí nad Labem. The entry on mindat.org states that the quarry operated until most likely 1938. This locality is the first reported find of Gismondine from the Czech Republic (Czechia), and this particular piece is the ONLY specimen of the material that we've ever seen. This small cabinet specimen features an exposed vug featuring white, vitreous, monoclinic crystals of the Gismondine Subgroup (likely Gismondine-Ca) measuring up to 6 mm. Gismondine minerals are rare members of the Zeolite Group, and display quality specimens are few and far between as most of the crystals you'll find are rather small, but this piece has excellent eye-visible crystals. A great historic rarity with an added value from the provenance, as it was mined in 1878 and comes with a fantastic old label from the major mineral dealer Lazard Cahn, of Colorado Springs, who lived from 1865 to 1940.
The piece was pictured in Collector's Guide to the Zeolite Group (written by Bob Lauf), but please note that the book is not included with this listing.
From the collection of longtime mineral collector Dr. Bob Lauf (Collection #464), the author of the Mineral Collectors Guide books (Schiffer Publishing), widely seen at mineral shows and libraries. Robert Lauf grew up in Chicago and attended the University of Illinois, ultimately receiving a Ph.D. in Metallurgical Engineering. His scientific career included over twenty years at Oak Ridge National Laboratory, where he conducted research on topics ranging from nuclear fuel, coal by-products, materials synthesis, microwave processing, sensors, optical materials, and biomineralization. He has been granted over forty U.S. Patents for his inventions, many of which have become successful industrial products. He is now a Registered Patent Agent and technology consultant.