Identification of pearls
The Mineralogical Museum of the University of Hamburg is offering an identification service for pearls using different X-ray methods: X-ray tests can show whether
- a pearl is natural or cultured
- a cultured pearl is bead- or tissue-nucleated
- a pearl is from marine or freshwater sources.
I. Bead-nucleated cultured pearls
X-ray diffraction unveils the internal structure of a pearl. With this method the shell-nucleus of a bead-nucleated cultured pearl is easily detected. The X-ray diffraction unit of the Mineralogical Museum Hamburg allows the direct observation of diffraction patterns of pearls (Lauegrams), thus leading to a fast and precise identification of bead-nucleated cultured pearls, e.g. Akoya or South Sea cultured pearls.
II. Natural pearls (oriental pearls) and beadless cultured pearls
X-radiographs reveal internal growth structures and thus are used for the identification of natural pearls (oriental pearls) and for non-beaded cultured pearls, e.g. Chinese cultured freshwater pearls.
III: Marine or freshwater pearls
X-ray luminescence of pearls is used to determine the environment of which a pearl comes from. Freshwater pearls fluoresce under X-ray excitation as against marine pearls which are inert to X-rays.
Costs and contact
Determination fees are assessed on a case by case basis. Please contact
Prof. Dr. Jochen Schlüter