Diamond Grading Report
Full 4Cs grading, proportions diagram, treatments and a photograph of the stone.
Learn more
GEM
Gemological Laboratory
Independent gemological laboratory · Since 2012
GEM
One laboratory for the whole luxury item: loose stones, finished jewelry and watches. Each report carries a unique number, barcode and QR code.
Our servicesFull 4Cs grading, proportions diagram, treatments and a photograph of the stone.
Learn moreSpecies and variety, natural or synthetic, color, measurements and treatment disclosure.
Learn moreThe finished piece: metal and its verification, weight, center and side stones, total carat weight and condition.
Learn moreReference, serial, movement, timekeeping, water resistance, parts originality and a final authentication result.
Learn moreGEM
GEM does not buy or sell the items it examines. Our only interest is an accurate report.
Calibrated instruments, master stones and a second review with quality control before any report is approved.
A unique number, barcode and QR code open the original record online, with the photograph taken at examination.
Diamonds, lab-grown diamonds, gemstones, jewelry and watches, examined under one roof and one standard.
Our team
GEM is an independent laboratory with a team of certified gemologists working to a single, consistent standard.
Israel · Dubai, UAE
Learn moreEvery item follows the same documented path. Each step is recorded with the examiner and the time.
The item is received, photographed and given a tracking number.
We determine exactly what the item is.
Laboratory tests matched to the item category.
Grades are assigned or authenticity is determined.
A second gemologist reviews the results; quality control checks the record.
A secure printed report with a unique number, barcode and QR code.
The record is published to the GEM registry for anyone to verify.
The quality of a diamond is described by the 4Cs. Here is what each one means.
How we evaluateGraded from D (colorless) to Z (light yellow or brown).
From Flawless to Included, based on inclusions seen at 10× magnification.
How well the proportions, polish and symmetry return light, from Excellent to Poor.
The weight of the stone. One carat equals 0.2 grams.
For Professionals
Jewelers, dealers, watch retailers and auction houses work with GEM through a business account: volume pricing, priority handling and a full online history of every report.
Open a business accountContact us to schedule a submission. We will explain the right report for your item and the expected turnaround.