The Gemological Collection of Abraham Gottlob Werner

The gemological collection of Abraham Gottlob Werner contains 1374 sample numbers for 25 different minerals with 38 gemological varieties, including 15 newly added numbers of samples, which were not recorded in the original catalog of 1823. In total, 168 samples were recorded as lost by the later researchers, 4 samples were taken for the chain for the rector of the university, samples of 2 different numbers in the catalog were exchanged for cut stones, and 3 times’ volume requisitions happened. A total of 256 sample numbers show discrepancies and therefore are not in accordance with the original record in the catalog. In the collection, 6.8% of the numbers are rock sample with embedded crystals, 20.7% of the numbers are in the form of crystal, 30.6% of the numbers are fragments, 11.6% of the numbers are grains, and the remaining 711 samples are cut. Except for Esa. No. 644a containing four cushion cut samples, all faceted cuts were recorded in the original catalog of 1823. However, the brilliant, oval, step, emerald, scissor, and radiant cut forms were invented after the gemological collection of Werner, which means 189 samples do probably not belong to the original collection. They could be from another collection due to the requisitions, or the later researchers of the collection added or exchanged the samples with new ones. The mineral names of the catalog from 1823 refer to Werner's mineral system, some of the mineral's names are not used anymore. With the development of mineralogy and gemology, the special names of the gemstones as varieties of minerals are gradually standardized. 51 samples are wrong identifications and 8 pieces of glass have been recognized. The zircon samples of the collection provide a research resource for the study of metamictization. Both color and density of zircon could be an indicator of the metamictization degree. The metamictization has a significant influence on the gemological properties of zircon. The green tone and low density c