| Central Coast Gemological Laboratory Services include cutting, appraisal, classes and gem sales. http://www.centralcoastgemlab.com/ |
| European Gemological Provides diamond, colored stone and pearls certification, analysis and consultations. http://www.eglusa.com/ |
| European Gemological Laboratory European Gemological Laboratory's is and international. http://www.egl.co.za/ |
| Gemological Institute of America The world’s largest and most respected nonprofit institute of gemological research and learning. http://www.gia.edu |
| GemWorld Provide opals, gemstones, collector stones, synthetics, cabbing and faceting rough, lapidary equipment and supplies. http://www.gemworld.com/ |
| Global Gemological Laboratory Diamond grading reports and appraisals. http://www.globalgemlab.com/ |
| Harold Weinstein Ltd. Gemological laboratory specializing in fine jewelry insurance, estate appraisals, and diamond grading. http://www.hwgem.com/ |
| International Gemological Institute The world's largest independent gem certification and appraisal institute and is renowned for its quality services, extensive experience and know-how. http://www.igi-usa.com/ |
| Kashmir Sapphires A network of gemologists, private collectors, and international financiers for the buying and selling of kashmir and burmese sapphires. http://www.kashmir-sapphires.com/ |
| Kim Jewels Specializing in customizable sterling silver and gemstone jewelry at affordable prices. http://www.kimsjewels.com/ |