Past conferences
Abstracts Library
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
Phase transformations as important markers for heat treatment detection in corundum and other gemstones
Detection of heat treatment of ruby and sapphire and other colour varieties of corundum is a major issue for the trade and laboratories alike. Heat treatment of corundum is commonl
Opal stability: a step toward detection
Opal is a gem of captivating beauty that stems from its complex microscopic structure composed mainly of silica. In the most striking specimens, the light diffraction from a three-
Diamonds and synthetic diamonds
Diamond is historically one of the most important gemstones, in terms of value, use and general appreciation. Diamonds were generally formed relatively early in the Earth’s Histo
Violet Diamonds from Argyle: New Insights into the Cause of their Unique Color
Until its recent closure, the Argyle mine in Australia has been the only source of uniquely colored violet diamonds produced during the 35 years of its operation. These diamonds th
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
Analysis of Myanmar golden-lipped cultured pearls using X-ray radiography, EDXRF, UV-Vis-NIR and Raman spectroscopy
Myanmar golden-lipped pearl oysters (Pinctada maxima) are well-known to be found at the Myeik Archipelago – formerly also known as Mergui Archipelago – in the Andaman Sea in so
FTIR Fingerprinting: a case study on mineral inclusion identification by FTIR applied on rubies from marble-hosted deposits
Fourier-Transform Infrared Spectrometry (FTIR) is a well-established analytical method in the field of gemmology (Suhner, 1979; Fritsch and Stockton, 1987; Smith, 1995; Beran and R
Causes of color in brown mammoth ivory
The mammoth species were once the largest terrestrial mammals in the world during the late Pleistocene (approximately 350,000 to 10,000 years ago), inhabiting the northern hemisphe
DNA Fingerprinting and age dating of historic natural pearls: a combined approach
Natural pearls are accidental formations in wild oysters. The lack of new supply in recent decades has meant that the trade is heavily dependent on old stocks of natural pearls, an
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
Past, Present and the Future of IGC
Exactly, seventy-one years ago, in the month of October, to be precise from the 23rd to the 25th of October 1952 in Lugano, Switzerland, the inaugural meeting of the International
Gemological and Luminescence Characteristics of Taaffeites from Mogok, Myanmar
Taaffeite is a rare gem that has been found in different localities such as Tanzania, Sri Lanka, China, and Mogok, Myanmar. Systematic research on the taaffeite from Mogok, Myanmar
Study of a historical Alexandrite from Paris school of mines collection
Rare are the scientific studies on exceptional gemstones belonging to museum collections. This investigation is part of an ongoing project, on the study of historic gems, of the Mi
Mapping underground rivers at the Copeton Diamond Field, New South Wales, Australia. Following these “deep leads” to further riches
In Australia’s ‘New England’, early gold and tin explorers discovered diamonds in their sluice boxes without realising their significance, but by the 1890s the Copeton-Bingar
Applications of Python for Spectroscopic Data Processing, Analysis and Machine Learning Modeling in Gemmology
Python, a powerful programming tool with extensive scientific computing capabilities, is being increasingly utilized in gemmological science. It is particularly well-suited for pro
Colour change Paraiba tourmaline from Brazil
In just a few decades Paraiba tourmalines have developed into one of the most valuable and sought-after gems in the world. Of particular interest are specimens from the legendary B
Quartz crystals from alpine fissures: their formation and the historical significance of alpine quartz as raw material for objets d’art
The central Alps, especially the central granite massifs (Aar Massif, Gotthard Massif, Mont Blanc Massif) in Switzerland and adjacent France are known since ancient times for their
Irradiation treatment and gamma-spectroscopy of morganite
The pink variety of beryl, morganite, is one of the most popular orangey-pink to pink gemstones. Its colour is attributed to manganese, both Mn2+ and Mn3+ (Nassau & Wood, 1968, Woo