Natural Diamond Grading Report
Full 4Cs grading, proportions diagram, treatments and a photograph of the stone.
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Independent laboratory · In the trade since 2012
Independent gemological laboratory · Since 2012
Certainty for every diamond, gemstone, jewel and watch.
GEM examines, grades and authenticates luxury items, and issues a secure report for each one that anyone can verify online.
2012In the gem and jewelry trade
10Certified gemologists
3Offices: Israel · Dubai · Russia
5Item categories under one roof
What we examine
Every stone has its own story
From colorless and fancy-color diamonds to sapphires, rubies and emeralds, each stone is examined, measured and documented by our gemologists.
How we grade
The most popular cut, prized for maximum brilliance and fire.
Among the rarest diamonds on earth; color intensity defines their value.
A step cut with open facets that reveals clarity at a glance.
Corundum in blue and every fancy color; in hardness second only to the diamond.
The green variety of beryl; its natural inclusions make every stone one of a kind.
Red corundum, the most valuable colored gem; chromium gives it its glow.
Traces of nitrogen create yellow tones, from faint to vivid canary.
GEM
GEM Reports
One laboratory for the whole luxury item: loose stones, finished jewelry and watches. Each report carries a unique number, barcode and QR code.
Our servicesLaboratory-Grown Diamond Report
Complete grading with clear identification as laboratory-grown and the growth method (CVD or HPHT).
Learn moreGemstone Identification Report
Species and variety, natural or synthetic, color, measurements and treatment disclosure.
Learn moreJewelry Certificate
The finished piece: metal and its verification, weight, center and side stones, total carat weight and condition.
Learn moreLuxury Watch Authentication Report
Reference, serial, movement, timekeeping, water resistance, parts originality and a final authentication result.
Learn moreGEM
Why certify with GEM
Independent
GEM does not buy or sell the items it examines. Our only interest is an accurate report.
Scientific method
Calibrated instruments, master stones and a second review with quality control before any report is approved.
Verifiable anywhere
A unique number, barcode and QR code open the original record online, with the photograph taken at examination.
One lab for all luxury
Diamonds, lab-grown diamonds, gemstones, jewelry and watches, examined under one roof and one standard.
Our team
Ten gemologists. One standard.
GEM reports are prepared by a team of ten gemologists holding internationally recognized credentials, each with years of specialized experience.
Israel · Dubai, UAE · Russia
Learn moreFrom intake to online verification
Every item follows the same documented path. Each step is recorded with the examiner and the time.
Intake
The item is received, photographed and given a tracking number.
Identification
We determine exactly what the item is.
Testing
Laboratory tests matched to the item category.
Grading & authentication
Grades are assigned or authenticity is determined.
Review & QC
A second gemologist reviews the results; quality control checks the record.
Report issued
A secure printed report with a unique number, barcode and QR code.
Online verification
The record is published to the GEM registry for anyone to verify.
Understand your report
The quality of a diamond is described by the 4Cs. Here is what each one means.
How we gradeColor
Graded from D (colorless) to Z (light yellow or brown).
Clarity
From Flawless to Included, based on inclusions seen at 10× magnification.
Cut
How well the proportions, polish and symmetry return light, from Excellent to Poor.
Carat
The weight of the stone. One carat equals 0.2 grams.
For Professionals
For the trade
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 account- Volume pricing
- Online history
- Priority handling
- Ready for your customers
- Verification in your listings
Frequently asked questions
A document that describes the identity and characteristics of your item as examined by GEM on a given date, with a unique number that links it to the original record in our online registry.
Have an item to examine?
Contact us to schedule a submission. We will explain the right report for your item and the expected turnaround.