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A large group of people outside on GIA’s Carlsbad, California campus.

Article

Guardians of Trust: GIA’s Innovative Research, Instruments and Services

Russell Shor, September 20, 2019

GIA’s services and instruments have grown in importance and impact as new gem treatments and laboratory-grown gems have entered the market.

A face-up view of a cushion cut diamond with blue color.

Article

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.

Figure 9. The parcel of rough spinel on the left, reportedly from Tajikistan, contains pieces weighing up to 48.5 g. The seven faceted spinels on the right (9.04–28.16 ct) were fashioned from some of this rough.

Purplish Pink Spinel from Tajikistan: Before and After Cutting

Nicholas Sturman, March 1, 2009

Purplish Pink Spinel from Tajikistan: Before and After Cutting

Figure 1. One of GIA’s new LA-ICP-MS corundum calibration standards sets (set number 1); the epoxy disk containing the set is 1.5 inches in diameter. NIST SRM 610 and 612 glass standards are included to account for trace and non-trace elements, such as those found in inclusions, that were not incorporated into the synthetic sapphire crystals grown for standards. Photo by Jennifer Stone-Sundberg.

Accurate Reporting of Key Trace Elements in Ruby and Sapphire Using Matrix-Matched Standards

Jennifer Stone-Sundberg, Timothy Thomas, Ziyin Sun, Yunbin Guan, Zachary Cole, Randy Equall, and John L. Emmett, January 26, 2018

Presents a group of corundum standards developed by GIA to improve the accuracy and efficiency of its laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) instruments.

Natural-color yellow sapphires with FTIR features of Punsiri-treated sapphire

“Punsiri”-type FTIR Spectral Features in Natural Yellow Sapphires

Supharart Sangsawong, Vincent Pardieu, Victoria Raynaud, and Sasithorn Engniwat, November 7, 2016

Testing of natural-colour yellow sapphires from Australia and Thailand with the FTIR features of “Punsiri” heat-treated material.

Article

Pyrope Garnet and Montana Sapphires Highlight Winter 2015 G&G

Russell Shor, February 1, 2016

G&G Brief presents an overview of the content of the Winter 2015 issue of Gems & Gemology.

Article

Corundum Source Types

Learn more about corundum sources and GIA’s source type classification system, detailing the relationship between source type and geographic origin.

Article

Spring 2015 G&G Examines Blue Spinel, Chinese Jewellery Design and the Latest in Synthetics

Russell Shor, June 12, 2015

G&G Brief presents an overview of the content of the Spring 2015 issue of Gems & Gemology.

Article

Summer 2015 G&G: Dual-Stars, Photomicrography Guide, Rubies from Tajikistan, New Micro-World Section

Russell Shor, August 14, 2015

G&G Brief presents an overview of the content of the Summer 2015 issue of Gems & Gemology.

Abstract Header from the 2009 issue of Gems & Gemology

Abstracts; Summer 2009

Brendan M. Laurs, Thomas W. Overton

This article, from the Summer 2009 issue of Gems & Gemmology, is a compilation of abstracts of important gemmology-related articles published outside of Gems & Gemmology.

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