| COMPANY NAME | CONTACT PERSON | CONTACT NUMBER |
| BIG LAB RESEARCH | Ben Hoo | 82024102 |
| GEMOLOGICAL IDENTIFICATION RESEARCH LABORATORY | Mohamed Sabir | 91067267 |
| NAN YANG GEMOLOGICAL INSTITUTE | Zeng | 90683118 |
| UNIVERSAL GEMOLOGICAL LABORATORY | Farhan | 91774997 |
| WALTER TAN | Walter Tan | 97979101 |
