Presentation at Swiss Gemmological Society about trip to spinel and corundum deposits in Tanzania in October 2009 by Dr. Walter Balmer and Dr. Michael Krzemnicki
2010 Swiss Gemmological Conference presentation by Jean-Pierre Chalain on diamond grading and testing practices at the Swiss Gemmological Institute (SSEF).
Christie’s Hong Kong Spring Auction lecture by Dr. Michael Krzemnicki. “Gemstones and the fascination of colour”
Talk given by Dr. Michael Krzemnicki in Hong Kong in 2010 about spinel, a gemstone increasingly in vogue. History, sources, origin determations, synthetics and treatments.
Talk on ruby treatments and terminology during CIBJO Ruby Day in Munich in February 2010.
Author(s): M.S. Krzemnicki
News from the SSEF Lab. 2010 Swiss Gemmological Society conference. Presentation by Dr. Michael Krzemnicki
Presentation on x-ray computed tomography during LMHC meeting in Bahrain in 2010.
Author(s) :M.S. Krzemnicki
Latest research on detection of low temperature treatment of pink sapphires. Presentation by Dr. Michael Krzemnicki of SSEF.
Abstract: A range of different materials has already been used as cores in beaded cultured pearls, and now two new alternative options, baroque shaped shell beads and Chinese freshwater cultured pearls, are being used. Experiments with beads of the latter, approximately 6.5 mm across, have been carried out with marine Pinctada maxima and Pinctada margaritifera oysters. After 13 months, nearly 200 pearls of each kind were harvested. Cross sections and further observations of resulting pearls are described. X-radiographs and X-ray microtomography are found to generally deliver clear evidence for identification. These pearls have beenfound to be very suitable for subsequent drilling. Natural pearls also have been used as nuclei for producing cultured pearls. The material used is either non-nacreous, brown or of an unattractive appearance. This new kind of cultured pearl is diffi cult to identify, because the radiographic structures of the natural cores are masking these cultured pearls.
Journal of Gemmology (2010)
Author(s): H.A. Haenni, M.S. Krzemnicki, L.E. Cartier
Eine Reise zu den Spinellen Tansanias. Gold’Or (2010)
Author(s): M.S. Krzemnicki