A Pink Sapphire with Questionable Heat Treatment
A pink sapphire weighing over 20 ct was recently submitted to Guild Gem Laboratories, and it presented a particularly ch...
GUILD Library
Knowledge Repository|40+ Years of Excellence
Research Publications
Academic Papers
Peer-reviewed research, conference presentations, and scholarly contributions advancing gemological science and practice.
An Unusual Inclusion Formation of Anatase and Rutile in Quartz
The study of inclusions within gem materials provides important insights into their crystallisation processes and the geological conditions of their formation. Recently, Guild Gem Laboratories gemmolo...
An Unusual Inclusion Formation of Anatase and Rutile in Quartz
The study of inclusions within gem materials provides important insights into their crystallisation processes and the ge...
'Sugar' Nephrite from the Altun Mountains, Xinjiang, China
Nephrite has a long history and profound culturalsignificance in China, along with a vast consumer market. In July 2025,...
Periodical Publications
Journals & Periodicals
Annual editions documenting the evolution of gemological knowledge, new treatments, emerging sources, and field research findings.
Visual Documentation
Field Expedition Gallery
Photographic documentation from GUILD's ongoing field operations worldwide—from mining sites to processing centers, capturing the real contexts where gemological knowledge begins.
