Occasionally, we encounter synthetic stones at SSEF that are submitted to us by our clients. Usually they are quite surprised by our result, as the issue of synthetic stones – at least in the coloured stone market – has very much vanished in peoples’ minds, and is often not anymore considered a real threa

first published in Facette 22 (February 2016) The Swiss Gemmological Institute SSEF received two blue translucent samples, a water-worn pebble, and a faceted stone of 1.72 ct cut from the same piece (Figure 1). The material was bought in Arusha (Tanzania) in December 2013 by Mr. Farooq Hashmi. Standard gemmolo

first published in Facette 22 (February 2016) Chrysoberyl is found in various colours, mostly yellow to green and brown due to iron, light green to bluish green (vanadium) or as the colour-changing variety alexandrite (due to chromium). In rare cases, chrysoberyl is also found in colourless and chemically rath

first published in Facette 21 (February 2014) Vanadium-bearing chrysoberyl of light green to saturated green colour has been known in the trade since the mid-1990s. Originally first described from Tunduru in southern Tanzania (Johnson & Koivula 1996, Pfenniger 2000), similar attractive “mint green” chr

by Dr. M.S. Krzemnicki, first published in Facette 21 (February 2014) In 2013, Ms. Carina Hanser from the University Freiburg im Breisgau in Germany successfully completed her bachelor thesis on cobalt-spinel from Vietnam. Under the supervision of Dr Krzemnicki, Prof de Capitani (University Basel) and Prof

first published in Facette 21 (February 2014) In 2013, SSEF received a lot of beautiful small so-called Pipi- pearls from the Pacific. These natural pearls are generally rather small, up to about 8 mm in diameter. This is not astonishing as they are formed within the rather small shell of the Pinctada macu