Low Temperature Heat Treatment of Mozambique Rubies
GIA’s next Gemstone Gathering is Feb. 25 in Bangkok
BANGKOK – Feb. 19, 2015 – Rubies have been treated for centuries using a traditional blow pipe technique to reduce the stone’s purplish tint and produce a better red or pink color. Vincent Pardieu, GIA’s supervisor of field gemology in Bangkok, will discuss modern methods and techniques for low temperature heat treatment that are being applied to new types of material such as pink sapphires from Madagascar and rubies from the Montepuez region of Mozambique during GIA’s (Gemological Institute of America) next Gemstone Gathering in Bangkok on Feb. 25.
Pardieu’s presentation will cover ruby burning techniques used in Thailand and Sri Lanka over the past few years. In January 2015, GIA researchers visited a facility in Sri Lanka to conduct heat treatment experiments on 12 rubies from Montepuez. Pardieu will discuss his team’s findings from the experiment, explaining how dark rubies can be turned into bright gems and how labs can detect ruby treatments.
Pardieu specializes in the origin determination of gemstones and has visited numerous gemstone-producing areas in South East Asia, Central Asia and East Africa and particularly the Ilakaka–Sakaraha sapphire deposits of southern Madagascar over the past decade. He has spent his career in leadership positions with gemological laboratories around the world, including in Thailand and Switzerland. His research and expertise have been the catalyst for numerous articles in GIA’s Gems & Gemology and various trade publications..
GIA’s Gemstone Gathering, a free event, begins at 6 p.m. on Feb. 25 in the “Crowne Room 1-3” on the 21st floor of the Crowne Plaza Hotel, Lumpini Park in Bangkok.