Optical Effects of Phenomenal Cabochons
Sharon Bohannon, November 11, 2016
Learn how the structure, inclusions and properties of some gemstones interact with light to create unusual visual effects.
Gems & Gemology’s 7 Most Unusual Encounters from 2019
Stuart Overlin, Brooke Goedert and Kellie Giordano, December 13, 2019
Check out some of the most interesting and unusual diamonds and coloured stones submitted to GIA’s laboratories in 2019.
Gems and Minerals from the Sub-Arctic
Sharon Bohannon, March 17, 2017
Circumnavigate the boreal reaches of the globe to explore gems from polar regions.
A Horse-Shaped Inclusion in Pink Sapphire from Mozambique
Charuwon Khowpong, August 9, 2018
Microscopic examination of a Mozambican pink sapphire reveals an inclusion with a surprising shape and composition.
Gemmological Characterisation of Sapphires from Yogo Gulch, Montana
Nathan D. Renfro, Aaron C. Palke, and Richard B. Berg, August 6, 2018
A look at the mining and distinguishing characteristics of this naturally vibrant blue sapphire.
Violetish Blue Spinel in Yellow Sapphire
Nathan Renfro and John I. Koivula, February 1, 2016
A singly refractive inclusion within a yellow sapphire proves to be spinel.
A Fantastic Display of Phase Changes in a Sapphire’s Fluid Inclusion
Nathan Renfro, John I. Koivula, and Elise A. Skalwold, April 28, 2016
Phase changes illustrate the temperature and pressure conditions in the fluid inclusion system of a Sri Lankan sapphire.
Autumn 2016 G&G: CVD Synthetic Diamonds Survey, Reversible Colour Change in Blue Zircon
Jennifer-Lynn Archuleta, October 31, 2016
A summary of the content found in the Autumn 2016 issue of Gems & Gemology.
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.
A study of the gems in ciborium from Einsiedeln Abbey
Stefanos Karampelas, Marie Wörle, Katja Hunger, Hanspeter Lanz, Danilo Bersani, and Susy Gübelin
The gemstones that adorn a late-16th-century ciborium from Einsiedeln Abbey in Einsiedeln, Switzerland.