Independent grading.

Every investment-grade stone is accompanied by a current report from a tier-one independent laboratory. We do not issue self-graded reports.

Accepted laboratories

• GIA — Gemological Institute of America (diamonds, coloured stones)
• SSEF — Swiss Gemmological Institute (high-end coloured stones, pearls)
• Gübelin — Gübelin Gem Lab, Lucerne (Kashmir / Mogok origin)
• AGL — American Gemological Laboratories (coloured stones)
• GRS — GemResearch Swisslab (rubies, sapphires)
• Lotus — Lotus Gemology, Bangkok (rubies, sapphires, spinels)

What a report includes

A laboratory report typically certifies: species and variety, weight to two decimals, measurements in millimetres, cut and shape, colour grade or descriptor, clarity descriptor, treatment status, and — for premium stones — country or geographic origin.

Re-certification

If you wish to re-certify a stone purchased from OPIKJEWELS at a different laboratory, we can arrange this on your behalf. Submission, insurance, and laboratory fees are at the client's expense; we charge no handling premium.