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1. Gemmological Association of Great Britain
2. Gemological Institute of America
3. American Gemological Laboratories
4. AGTA Gemological Testing Center
5. SSEF
6. Gubelin Gemological Laboratories
7. GemResearch Swisslab
8. The Gem and Jewelry Institute of Thailand
9. AIGS Gemological Laboratory
10. The Russian MSU Gemological Center