top of page

Bellerophon's Past Research


Vibrational properties of OH groups associated to divalent cations in corundum (α-Al2O3)

The infrared spectra of synthetic corundum (α-Al2O3) samples either doped directly with divalent cations (Mg2+) or containing divalent cations formed by reduction of trivalent cations in H2 gas (Co2+, Ni2+ ) display broad OH stretching bands at ~3000 cm-1 due to the 25 structural incorporation of trace amounts of hydrogen. Experimental spectra recorded from some natural sapphires display a similar absorption band associated with a dominant absorption at 3161 cm-1 , and some beryllium-diffused corundum crystals show a band at 3060 cm-1 . All of these also display smaller and generally narrower bands between 1900 and 2700 cm-1 , whose natures are poorly defined. In this work, the atomic-scale structure, relative 30 stability and infrared spectroscopic properties of a series of OH defects in corundum (αAl2O3) are theoretically investigated at the density-functional theory level.

Accepted at The European Journal of Mineralogy ( on 4/09/2023.

Induced Amorphisation of Zircon Through Irradiation.png


182 Pink sapphire from Madagascar (Ilakaka) comprising of 74 heat-treated in our Bangkok facilities (from 500 to 1400 oC) and 108 not heat-treated as well as 258 Rubies from Mozambique both totalling 369 carats were irradiated using a 60Co γ-ray source from 1 kGy up to 576 kGy for a maximum period of 37 days. Gemmological properties have been collected before and after using standard and advanced gemmological testing. The results show that the disorder degree of Zircon in Sapphire may increases without visible damage to the structure depending on the irradiation dose.

Publication date: 24.08.2022 Reference number: TAZIR24082200A1


Excitation Emission Matrix Spectroscopy of Gemstones

Excitation Emission matrix spectroscopy at Bellerophon Gemlab. Thanks to this new spectrometer a whole new field of research open with enormous potential. We collect fluorescence spectra from 650 different excitation wavelengths, that we combined to have a 3D spectra of the matrix. We already managed to tailored our existing instruments to be matrix specific, such as reducing fluorescence in Raman spectroscopy for ruby as well as detecting heat treatment in corundum on photoluminescence.

Still ongoing research for publication.

fluo 2.png

Fluorescence Spectrophotometry Quantification

Fluorescence or its absence carries very important information about a gemstone: its paramagnetic crystal defects as well as its growth history. Quantification of paramagnetic defects in different gemstones: fluorescence quantification allows a much more accurate authentication, being at the forefront as the first laboratory to use deep UV imaging as a mandatory analysis coupled with a spectrophotometer.

Research waiting for publication.

World Record Ruby 55 carats.png

Estrella de Fura the World Record Ruby: Its creation & its analysis

The "Estrela de Fura" is one of the most important rubies discovered in the history of mankind, of our generation, and probably of many generations after. This 101 carat single crystal rough ruby may well define the quintessence of magnificence and be considered the paragon of perfection achieved by nature over the last 600 million years. This is the first time that a ruby has been cut with the help of such a panel of experts. As far as it is known, never before has a ruby been digitized from all angles: physically, optically, and with its gemmological properties integrated. A new generation of gemmologists and gem cutters is born.

Auction at Sotheby's New York the 8 june 2023

mada cobalt spinel 2.png

New production of Cobalt blue spinel close to Moramanga in Madagascar

New production of blue spinel close to Moramanga in Madagascar present internal features previously only seen in Vietnamese spinel. Chemistry of trace elements notably Cobalt, Iron, Zinc and Manganese enable so far a clear separation between the two deposits. This new deposits has been carefully referenced and now available for origin determination at Bellerophon Gemlab.

Not planned to be published

spinel O 3.png

Geographic Origin Determination of Spinel

Research and presentation of geographic origin determination of spinel at the China International Gems & Jewelry Academic Conference in Beijing. The one hour presentation is available on our latest news page. 

CIJF Beijing the 15 november 2019

H 3.png

Heat Treatment Research Facility Opening

State-of-the-art heating equipments has been added to inhouse to our research department. Our treatments equipments are utilise only to better understand enhancement as well as to improve treatments detection.  

Bangkok the 11 October 2019

Unexpected error... Please try again later

bottom of page