The following are good resources:

• de Goutière Jewellers, Victoria, BC
• The Gemmological Institute of America
• The American Gem Society
• British Gemmological Association
• Canadian Gemmological Association
• Instituto Gemológico Español
• Gemmological Association of Australia
• The Scottish Gemmological Association
• Instituto Brasileiro de Gemas e Metais Preciosos
• Laboratoire Français de Gemmologie
• Gem Testing Laboratory Athens
• Danny J Sanchez
• Gemology On-Line.com
• Directory of BC Lapidary Clubs
• Beyond 4Cs, free gemmology courses and resources
• Odile Civitello, (evaluation, gemmology, consultant)
• Lisa Rose Weaver (gem buying, gemmology, quality control)