A Photo Survey of Inclusions in Fossiliferous Amber
For many, fossiliferous tree resin, primarily amber, gained wide visibility to the public in 1993 where it was prominently featured in the movie, Jurassic Park
Shining light on “480 nm band” diamonds: Gemmological characteristics of an unusual group of diamonds with yellow and red luminescence
Fancy colour diamonds that derive their colour from nitro- gen-related defects (such as N3/N2 centers or C-centers) are relatively common and well-studied
HFSE-enriched sapphires of gem quality: A combined FTIR and trace element study and implications for heat treatment detection
Gem-quality sapphires containing ‘exotic’ elements such as Sn, Nb, Zr, Ta, W, are of special interest in gemmological research, as the concentration of these so-called high-fie
Historic Emeralds and their Geographic Origin: A Retrospective Study
When it comes to the geographic origin of gems, curiously enough, historians sometimes put forward provenance without any documentary or scientific proof
Color enhancement in yellow sapphire
Natural yellow sapphire is colored by one or the combination of two different chromophores, Fe3+ and the trapped hole-Fe3+ (h• -Fe3+) colour center. Fe3+ chromophore is typically
Additional Observations on Unstable Color in Padparadscha Sapphires
For the past few years laboratories have been testing the color stability of padparadscha sapphires. It became an issue because we realized that the orange color in some pads was u
Crystal structure of nano inclusions in blue sapphire from Diego Suarez, Northern Madagascar
Nano inclusions in unheated blue sapphire (Diego Suarez, northern Madagascar) containing naturally occurring beryllium have been studied. Tabular nano inclusions with a diameter of
Influence of Irradiation on Colour Modification and Colour Stability of Rubies: A Preliminary Study
Ruby is the chromium-bearing red colour-variety of corundum Al2 O3 . Since historic times, ruby is highly popular in the gem and jewellery market because of its highly saturated re
Low Temperature Heat Treatment of Burmese Ruby
Detection of low-temperature heat treatment (below 1200°C) in ruby and sapphire can present challenges to gemologists, as alterations to the material are often subtle. In this stu
Milky appearance of Geuda sapphire from Sri Lanka
Sri Lanka is famous for gems since several thousand years. Almost corundum varieties have been found in Sri Lanka including the rough of Geuda which has also given considerable att