Past conferences
Abstracts Library
Nacreous Blister Pearl Discovered in Edible Oyster (Crassostrea gigas)
A baroque pearl with a gray, nacreous appearance was discovered attached to the interior of an edible oyster while the author was enjoying a meal at home. The oyster had been purch
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
Purple to bluish grey chalcedony from Ethiopia
In the past 15 years, Ethiopia has repeatedly gained attention for a variety of new gem finds. In 2008, a large deposit of white play-of-colour opal was found (Rondeau et al., 2010
Proposed New Filler Type for Emerald Fracture Filling: Design, Detection, Differentiation, Disclosure
Fracture filling is common in gem trading to enhance gemstones’ beauty and / or durability. Common textbook examples are (lead) glass filling of rubies and diamonds, polymer/resi
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
Treated jadeite-jade: Unusually bright fancy colours
Jadeite-jade is a precious ornamental stone that has been valued as the topmost decorative stone and has been used in jewelry, carvings, and other ornamental objects by many cultur
A brief history of synthetic diamond researches in Japan
Research on diamond synthesis started in early 1960s in Japan, following GE’s success in 1955. The research was most active between 1980 and 2000 in Japan, triggered by success i
Cobalt spinel from Bai Buoi mine, Yen Bai, Vietnam
The cobalt bearing spinel from Lukande, Tanzania, discovered in 2019, has attracted much attention and several papers were published recently (Stephan & Muller., 2022, Krzemnicki e
A study of nickel-bearing type Ia diamonds
We present a detailed FTIR and PL spectroscopic study (i.e. at 298 and 77°K) of a large number of colorless (i.e. color D to G) type Ia diamonds (i.e. >200), showing the presence
Study and investigation of garnet from Balangir in Odisha, India
n the present study investigation of almandine-pyrope garnet, found in the Khaliapali village (20.8639° N, 83.4708° E) located in Balangir Tehsil of Balangir district of Odisha s
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
The Banjarmasin Diamond in Amsterdam – War Booty from Borneo
The Banjarmasin diamond in the collection of the Rijksmuseum in Amsterdam plays a questionable role in the history of the Dutch occupation of Southern Borneo. Confiscated from the
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
Microfeatures of Beryl Group Gems including the Newest Mineral Variety, Johnkoivulaite
Beryl group minerals often provide clues to their pegmatitic origin in the suite of inclusions contained within such gems. They regularly showcase examples of pegmatitic minerals s
The Importance of Research for Gem & Jewellery Industry
Research has always been an essential tool for business leaders who always realise that the consuming public is active, and hence, research investment could help lead their busines
Mechanism and Application of High-Temperature Copper Diffusion in Surface Recoloring of Labradorites
Feldspar, with the chemical formula of [KAlSi3 O8 ]x[NaAlSi3 O8 ]y[CaAl2 Si2 O8 ]z (x + y + z = 100), is one of the most important rock-forming minerals in the earth’s crust, and
Sulfur-based species induced photochromism in sodalite
Sodalite Na4 (Al3 Si3 O12)Cl is a natural aluminosilicate mineral that contains sulfur or sulfur-related defects, known as chromophores (Reinen et al. 1999; Fleet et al. 2010). Hac
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-
A Review and Synthesis of the Geology and Gem Resources of Granitic Pegmatites in Southern California, USA
Gem-bearing pegmatites in Southern California are hosted by the Peninsular Ranges batholith, and occur in ten districts in San Diego and Riverside counties (Figure 1a and Table 1).
