Past conferences
Abstracts Library
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-
Geographic Origin Determination of Fei Cui: A comparison of high-quality green Fei Cui from Myanmar, Guatemala, and Italy
Fei Cui is a kind of jade that is defined as a granular to fibrous polycrystalline aggregate composed solely, or principally of any of the following or any combination of the follo
A study of Chikayama’s gem and mineral collections and building a gem museum
Based on the belief that “a gemstone is art and science,” Mr. Akira Chikayama devoted his life to gemological research and study for the benefit of people involved in gemstones
Rose Quartz: Journey Into the Nano-Jungle
Massive rose quartz is a readily available mineral ranging in colour from pink to salmon- or lavender-pink (Figure 1). Given its popularity in the market, it might be assumed that
Fingerprint differences between Emeralds from two main zones of production in Colombia in response to input from their host rock
Although there is information about techniques to separate Colombian emerald material from that of other countries, not much information is available on how to differentiate Colomb
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
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
Initiatives for sustainable pearl cultivation in Japan
Natural pearls are a gift from nature. On the other hand, cultured pearls are a symbol of humanity and nature. Skilful pearl smiths and rich nature are needed to cultivate beautifu
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
CVD Rough Diamonds Striae Grading Approach based on Deviated Optical Performance of Polished CVD Diamonds
Diamond’s optical performance cognition and scientific descriptions are based on the three key attributes: brilliance, fire and scintillation. Brilliance is an illusion caused by
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
Baltic amber and its inclusions: an insight into the origin and nature of the trapped material
Amber is a fossilised resin from ancient trees (coniferous and deciduous), which underwent the process of fossilisation in various epochs and depositional environments. Until the p
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
Origin Identification Characteristics of High-quality Green Jadeite
Currently occurrences of jadeite mainly include Myanmar, Guatemala, Russia, Kazakhstan and Japan. Origin has a great impact on the price of high-quality green jadeite and at presen
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
Overview of the “GEM” special exhibition at the NMNS
A special exhibition “GEM” was held at the National Museum of Nature and Science (NMNS), Tokyo, from February 19th to June 19th, 2022. The exhibition covered all aspects of gem
Colour varieties of gems – where to set the boundary?
In theory it is simple: a gemstone is a mineral formed in nature by geological processes and, as such, it has a mineralogical name that is scientifically defined and accepted by th
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
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
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
