Past conferences
Abstracts Library
Blue sapphire from Malacacheta of Minas Gerais, Brazil
Malacacheta, located in Minas Gerais, Brazil, is renowned for its alexandrite deposits and com-plex geological setting
Low Temperature Heat Treatment of Madagascar Sapphire
One of the challenges facing gemologists today is the detec- tion of low temperature (below 1200°C) heat treatment in corundum (Hughes et al., 2017)
A convincing glass imitation of larimar (pectolite)
Larimar, a massive blue variety of the mineral pectolite, belonging to the wollastonite group of minerals is known in the trade for few decades now
Advancing Fei Cui Origin Authentication: A comparison of green fei cui from Myanmar, Guatemala, Italy and Russia
In recent years, an increasing number of sources of fei cui, such as Guatemala, Italy and Russia, have entered the Chinese market, leading to a growing demand for precise origin de
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
Colored gemstones of metamorphic origin: Progress report in understanding how they crystallize at depth in East Africa, the Hindu Kush, Pamir Mountains, and the Middle-Urals Ring Structure
It is difficult to reconcile the existence of deposits of trans- parent gems of metamorphic origin with the observation attributed to Robert Boyle (1627–1691) that the best crys-
Diamonds from Than Lwin River near Mong Hsu, Myanmar
Sixteen rough diamonds were acquired in 2023 by co-author TTS from a gem dealer linked to Mong Hsu, Shan State, Myanmar
Nitrogen aggregates in yellow HPHT and CVD synthetic diamonds
Yuri Shelementyev, Galina Kriulina, Olga Yarapova, Viktor Vins, and Alexander Stolyarevich
Pink-orange gem quality euclase from Bahia, Brazil
Euclase, monoclinic crystal system—is a seldomly occurring mineral and with a Mohs hardness of 7 and a perfect cleavage to (010) rarely faceted for use in jewellery, but crystal
Study of “amethysts” from the French Crown Jewels
Stefanos Karampelas, Eloïse Gaillou, Annabelle Herreweghe, Ugo Hennebois, Farida Maouche, Romain Bolzoni, Steven Riou, Quentin Dartois, Bérengère Meslin Sainte Beuve, Christelle
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
Zoisite and its many color
The mineral zoisite is a calcium alumosilicate belonging to the class of silicates, more exactly sorosilicate minerals
Geographic Origin Determination of Natural Yellow Sapphires: The Preliminary Study
Determining the geographic origin of yellow sapphires plays a critical role in the gem trade, as origin often dictates both perceived quality and market pricing
Color Genesis Analysis and Characteristics for Origin Identification of Purple Jadeite
Purple jadeite, renowned for its distinctive purple hues and rich cultural connotations, is highly admired and sought after
Hessonite garnet from Angul district of Odisha, India
This study describes hessonite (Fe-bearing variety of grossular garnet), found in the Birlamunda village, located in Palalahada tehsil of Angul district of Odisha state
Application of Fibre Optics Reflectance Spectroscopy (FORS) for the determination of mineral pigments in jasper
The identification of pigments is carried out routinely mostly by X-ray diffraction, FTIR and Raman spectroscopy as well as visible absorption
Noble gas in corundum: interests in gemology
Noble gases —elements of the last column of the periodic table—are chemically defined by their full outer electron shells, making them highly inert and very volatile under ambi
An approach to understanding the factors in the emerald enhancement clarity grading system used at CDTECGemlab
Emerald is the green variety of beryl, with its distinctive color resulting from trace amounts of chromium, vanadium, and iron
History of Garnet Mining and Cutting in the Austro-Hungarian Monarchy
Bohemian garnets, i.e., chromium-bearing pyropes, are found in several jewellery pieces from the Migration Period (circa 400 to 600 A.D.), and only a small number of jew- els conta
Gemological Characteristics of New Transparent Brown Sapphire
A newly observed variety of faceted transparent brown sapphire has recently entered the gem market, prompting gemological attention due to its highly unusual appearance
