The piece is stunningly beautiful, with a rich, natural, bright silver patina and robust crystal form. Such 3-dimensional and robust crystals are EXTREMELY uncommon from any locale, including Kongsberg as rich and ancient as it was. The crystal atop measures just over 2 cm in height, and looks "twisted in the middle." It is spinel-twinned, very clearly and dramatically. AND, IT SITS on a tiny knob of calcite matrix so it is not just a loose single crystal, but has context. As a bonus accent, it has a little wire silver to the lower-right side, just to show off. Literally, everything is here to make this a WORLD CLASS thumbnail specimen. It has rare habit, desirable historic locality, beauty, robust crystal form and size, and is a FULL thumbnail. It is complete all around and pristine. Add to that the pedigree, and it gets better. This was owned by the industrialist Carl Bosch by circa 1900 (see his bio at: http://www.minrec.org/labels.asp?colid=205
). According to the Mineralogical Record biography: "In 1908 Fritz Haber told BASF of his ammonia synthesis process, and Bosch was assigned the task of developing it on an industrial scale. By the end of 1913 he had completed the the monumental job, the largest single undertaking in the history of chemical engineering. Bosch was awarded the Nobel Prize in Chemistry in 1931 for his work on high-pressure synthesis." His original handwritten label survives and is included, noting dates on both the front and the reverse (as well as some other comments I cannot make out, in shorthand). He died in 1940, but his son loaned the collection to Yale for some years, and in the end sold to the Smithsonian, in 1966. Note that this specimen was number 1265 for Bosch, an early number dating his acquisition to the 1890s (he owned over 25, 000 specimens by the end). The date on the front of the label refers to, I think, the prior history of the piece or its first sale to market in 1878. On the back of the label are notes including the date of 1877, possibly its year of discovery. Also in code, is the price he paid for it. By the 1990s, the specimen had been exchanged out of the Smithsonian (label included) and was in the collection of Dr. Gene Meieran, a collector of many suites including fine silvers. I exchanged/bought it from him in about 1999-2000, and sold it immediately into a European collection. However, that person recently decided that it was his ONLY thumbnail, and he did not collect thumbnails, so out it came to me in a later exchange. This specimen is one of the finest thumbnails I have ever handled (twice now), and one of my favorite silvers of any size, period, for a number of reasons as given above. I stand on that statement!