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1. Zenhokyo
2. The Russian MSU Gemological Center
3. The Gem and Jewelry Institute of Thailand
4. SSEF
5. Hong Kong Gems Laboratory
6. Gubelin Gemological Laboratories
7. GemResearch Swisslab
8. Gemological Institute of America
9. Gemmological Association of Great Britain
10. Gem Studies Lab
11. European Gemological Laboratory
12. American Gemological Laboratories
13. AIGS Gemological Laboratory
14. AGTA Gemological Testing Center