Hausmannite (rare historic specimen)

Item Description

An important old-time specimen of the manganese oxide, Hausmannite from the type locality for the species, Oehrenstock, Thuringia, Germany. The entry for this locality on mindat.org says that the earliest mention of mining at Oehrenstock goes back to 1311, and you have to believe that people were mining / digging there for years prior to it appearing in writing. This is an highly important old time manganese deposit, and specimens are certainly sought after by knowledgeable collectors. This small cabinet specimen is essentially a solid mass of Hausmannite, featuring some excellent, sharp, well-formed, dark grey-black pseudo-octahedral crystals of Hausmannite measuring up to about 7 mm at the longest dimension, which are sitting in a partial vug on the top/display side of the specimen . A choice example of this historic material. For reference, Hausmannite wasn't described until 1813 (at least 500 years after mining was taking place at Oehrenstock), when it was originally called "blättricher Schwarz-Braunstein" = foliated black-brownstone, and it officially named Hausmannite in 1827.
From the collection of longtime mineral collector Dr. Bob Lauf (Collection #1613) with great historic labels from the collection of John L. Parnau and Dr. Friedrich Krantz, of the famous Krantz mineral business in Germany (which is still in operation today). Dr. Lauf is the author of the Mineral Collectors Guide books (Schiffer Publishing), widely seen at mineral shows and libraries. He 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.