Article Search Results

Synthetic Ruby Overgrowth on Natural Corundum

Article

Analysis of Synthetic Ruby Overgrowth on Corundum

Sudarat Saeseaw, Vincent Pardieu, Vararut Weeramonkhonlert, Supharat Sangsawong and Jonathan Muyal, June 25, 2015

Analysis of synthetic ruby overgrowth on corundum, using analysis of inclusions, UV-Vis-NIR and EDXRF spectroscopy, and LA-ICP-MS.

Faceted Cobalt-Diffused Spinel and Polished Plate Samples

Article

GIA Lab Reports on a New Cobalt Diffusion Treatment of Natural Spinel

Sudarat Saeseaw, Vararut Weeramonkhonlert, Charuwan Khowpong, Nattida Ng-Poorsatien and Supharat Sangsawong, Victoria Raynaud, and Claire Ito, June 11, 2015

Report on a new cobalt diffusion treatment of natural spinel, using analysis of inclusions, UV-Vis-NIR and EDXRF spectroscopy, and LA-ICP-MS.

Article

Low-Temperature Heat Treatment of Mozambique Ruby

Vincent Pardieu, Sudarat Saeseaw, Stanislas Detroyat, Victoria Raynaud, Supharat Sangsawong, Thitima Bhusrisom, Sasithorn Engniwat and Jonathan Muyal, April 28, 2015

Report on changes in Mozambique ruby following low-temperature heating, observed using inclusion analysis, FTIR spectroscopy and LA-ICP-MS.

Article

New Nigerian Source of Blue Sapphire

Vincent Pardieu, Supharart Sangsawong, Jonathan Muyal, Nicholas Sturman, August 22, 2014

A preliminary report on blue sapphires from a new deposit in Nigeria's Mambilla Plateau.

Infrared mapping data of an HPHT-grown synthetic diamond wafer.

Article

Infrared Microscopy Applications

Ren Lu, January 9, 2013

Explores the usefulness of this technique in the mapping of defects and spectral features, the determination of colour origin, and the identification of synthetic and treated diamond melee.

Rubies and sapphires from Didy in Madagascar were recently discovered by timber loggers in a remote jungle covered area in the North East of Madagascar. Some very fine, large and clean rubies and blue sapphires were produced from the new deposit.

Article

Ruby and Sapphire Rush Near Didy, Madagascar

Vincent Pardieu and Nirina Rakotosaona, October 15, 2012

An expedition to investigate this new deposit revealed that their morphology and gemmological properties are reminiscent of blue sapphires from Mogok in Burma or Tunduru in Tanzania.

This 0.88 carat synthetic nano-polycrystalline diamond was grown using a multi-anvil press by a new sintering process and faceted into a round brilliant stone.

Article

Transparent, Faceted Nano-Polycrystalline Synthetic Diamond

Elise A. Skalwold, Nathan Renfro, Christopher M. Breeding and Jim Shigley, July 25, 2012

A preliminary examination of a new highly transparent synthetic diamond material not produced by CVD or traditional HPHT diamond synthesis methods.

Image taken in Carlsbad using the new L-Box for one of GIA’s research diamonds. The L-Box environment creates a good replication of how a diamond is viewed in real life.

Article

New Tool for Diamond Appearance Research

Al Gilbertson and Ilene Reinitz, June 13, 2012

The L-Box™ can be used to compare the appearance of two or more diamonds, or fitted with a camera to capture a series of photos while the objects are moving. The images can be combined to build a high-resolution or 3D video.

The flat fragment of a broken sapphire crystal (approximately 20 carats) displays bands of fine blue colour alternating with whitish bands of minute particles, and its centre is filled with “chocolate” brown silk.

Article

Sapphire Rush Near Kataragama, Sri Lanka

Vincent Pardieu, Emily V. Dubinsky, Supharart Sangsawong and Boris Chauviré, May 2, 2012

Details the sapphire mining and trading situation at this newly discovered deposit, including descriptions of the area's geology and samples observed during the expedition.

The stones in these earrings have the appearance, colour and gemmological properties of fine-quality jadeite. However, Raman analysis showed they were actually omphacite.

Article

The Jadeite/Omphacite Nomenclature Question

Shane F. McClure, April 12, 2012

An exploration of the distinction between jadeite and omphacite, plus GIA's current policy concerning the definition of these stones.

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