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Krzemnicki M.,SSEF Swiss Gemmological Institute | Friess S.,Gloor Instruments AG | Chalus P.,Hoffmann-La Roche | Hanni H.,SSEF Swiss Gemmological Institute | Karampelas S.,Gubelin Gem Laboratory
Gems and Gemology | Year: 2010

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. © 2010 Gemological Institute of America. Source


Karampelas S.,Gubelin Gem Laboratory | Michel J.,Johannes Gutenberg University Mainz | Zheng-Cui M.,Gubelin Gem Laboratory | Schwarz J.-O.,Johannes Gutenberg University Mainz | And 4 more authors.
Gems and Gemology | Year: 2010

X-ray computed microtomography reveals the internal features of pearls with great detail. This method is useful for identifying some of the natural or cultured pearls that are difficult to separate using traditional X-radiography. The long measurement time, the cost of the instrumentation, and the fact only one pearl at a time can be imaged are some of this method's disadvantages. © 2010 Gemological Institute of America. Source

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