Past conferences
Abstracts Library
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
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
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
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
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
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
Explanation on Yellow, Green and Brown Coloration Series of Basalt Related Bangkaja Sapphires
The basalt related Bangkaja sapphires, excluding the black star ones, commonly occur in three coloration series, i.e., the yellow, the green and the brown. Two representative sampl
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
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
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
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
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
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).
Investigating the Provenance signature of Tourmaline-Bearing Turquoise in the Kuh Zar Gold Deposit, Semnan Province, Iran
The Neyshabur reserve in northeast Iran is renowned for its production of Persian turquoise, yet it is not the sole deposit associated with this valuable gemstone. The Kuh Zar mine
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
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
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
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
A nuummite occurrence from kangerluarsuk in the Maniitsoq Region, West Greenland
K. I. Giesecke was the first to recognize the beauty of the iridescent amphibolitic gemstone Nuummite in 1810 when he collected samples from the island Simiuttat in the Nuuk area,
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
