A laboratory, and nothing else
The International Jewelry Institute exists to describe gem materials accurately and to say so in writing. We take no position in the trade: we do not buy, sell, appraise for sale, or accept payment tied to a grade.
Our graders work from published standards, on instruments calibrated to master sets, in five laboratories that grade the same stone the same way.
Standards and accreditation
The laboratory quality standard for testing and calibration, held for diamond grading and gem identification scopes.
Colour masters traceable to a single reference series, recalibrated annually and cross-checked between laboratories.
Balances, refractometers and spectrometers on a documented calibration schedule with retained records.
Sealed control stones circulate between the five laboratories each quarter. Deviations are investigated, not filed.
Graders are certified internally, re-examined annually, and rotated between benches to prevent drift.
Every issued report is retained with its photographs and plots, and can be reissued on proof of ownership.
Accreditation numbers and certificate scans are placeholders for the institute’s own records. Replace them with the current documents before publication.
Where the rules come from
Published standards
Grading nomenclature and tolerances follow published international practice. Where we depart from it, the report says so on its face.
A standards committee, not a sales desk
Changes to grading practice are decided by the standards committee and are published before they take effect.
Complaint and review
Any client may request a review grading. The stone is re-examined by graders who did not see it the first time.
“A grade is only worth the discipline of the person who could have written a kinder one.”