Research Library

How to get the blues of the pink: detection of low temperature treatment of pink sapphires

Latest research on detection of low temperature treatment of pink sapphires. Presentation by Dr. Michael Krzemnicki of SSEF.

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Appearance of new bead material in cultured pearls

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

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Interesting muscovite specimens from Pakistan: epitaxial incrustation and pseudomorphism after beryl

Interesting muscovite specimens from Pakistan: epitaxial incrustation and pseudomorphism after beryl. Published in the Journal of the Gemmological Association of Hong Kong (2010).

Author(s): M.S. Krzemnicki

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Künstliches Glas mit interessantem Farbeffekt – Grüsse aus dem Weltall oder doch sehr irdisch?

Künstliches Glas mit interessantem Farbeffekt – Grüsse aus dem Weltall oder doch sehr irdisch?. Gold’Or (2010)

Author(s): M.S. Krzemnicki

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Verre artificiel changeant de couleur – Une pierre “extraterrestre”

Verre artificiel changeant de couleur – Une pierre “extraterrestre”  Gold’Or (2010)

Author(s): M.S. Krzemnicki

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X-ray computed microtomography: distinguishing natural pearls from beaded and non-beaded cultured pearls

Abstract: The distinction of natural from cultured pearls traditionally has been based on X-radiography. X-ray computed microtomography (μ-CT) has recently been applied to gain more insight into pearl structures. Using this technique, this article presents features observed in a selection of natural pearls and beaded and non-beaded cultured pearls. Based on these observations, μ-CT is shown to be a powerful tool for pearl identification.

Gems & Gemology (2010)

Author(s): H.A. Haenni, M.S. Krzemnicki, P. Chalus, S. Karampelas, S.D. Friess

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