Abstract Identification Test for Copper-bearing Gemstones (Copper-Andesine and Paraiba-type Tourmalines) Using Copper-Isotope Ratio Determinations by Femtosecond Laser Ablation-MC-ICPMS *Gisela Fontaine, *Kathrin Hametner, *Detlef Günther and **Adolf Peretti *ETH Zürich, Department of Chemistry, Wolfgang Pauli Strasse 10, CH-8093 Zurich, Switzerland, **GRS Gemresearch Swisslab AG, Rue du marché 12, 1204 Geneva, Switzerland Cu-bearing gemstones including Cu-bearing Plagioclase […]
Eur. J. Mineral. 2008, 20, 965–973 Published online July 2008 Johachidolite, CaAl[B3O7], a mineralogical and structural peculiarity Milen KADIYSKI1, Thomas ARMBRUSTER1,*, Detlef GÜNTHER2, Eric REUSSER3 and Adolf PERETTI4 1 Mineralogical Crystallography, Institute of Geological Sciences, University of Bern, Freiestr. 3, 3012 Bern, Switzerland *Corresponding author, e-mail: email@example.com 2 Laboratorium für Anorganische Chemie, ETH Hönggerberg, HCI, […]
By Dr. A. Peretti and W. Bieri For the last couple of years, the appearance of lead-glass treated rubies has been widely recognized in the trade. The treatment is primarily used to enhance clarity in rubies or pink sapphires of lower commercial value. This treatment has been regularly seen at the GRS laboratory in rubies […]
GRS proudly announces that it has completed an in-depth research program including several thousand samples of sapphires from various mining areas in the Mogok region of Burma (Myanmar). Intensive study of the inclusion properties in sapphires from these different mining areas allows GRS to add more specific geographical origin information. This information includes the mining […]
GRS announces that it has completed its research on “Paraiba tourmalines”. Paraiba tourmaline is a Cuprian-Elbaite of “neon-colors” of pastel greenish-blue to blue hue from the origin of Brazil (lit. 1). Such tourmalines, however, have recently become known from various other origins. The trade had to settle the question whether these tourmalines from these different […]
The colour of the Be-treated sapphire matches other types of conventional heated sapphires (low to medium tone, medium saturation, not dark, no greenish overtone, good transparency and brilliancy). The identification occurred during routine Beryllium-testing at GRS. Testing in immersion did show a slight discoloration from blue to grey in the rim of the sapphire. No […]
A faceted approx. 1 ct Be-treated blue sapphire (acquired 2 weeks ago from the market, sold as Be-treated) was cut in half. The half-cut sapphire provided the possibility of measuring the penetration of the Beryllium into the sapphires body (length 5mm and with 3mm). Two profiles were measured across the sample perpendicular to each other, […]
Dr.A. Peretti receives the title of a European Geologist, Euro.Geol from the Federation of European Geologists. The title is a strongly protected professional title including checks CDP (Conitnuous Professional Development). It is mentioned in the GRS gemmological reports in the future as “European Geologist” or EurGeol togehter with the gemmological titles “FGG” and “FGA”.