Diamond Certificates
Understanding Diamond Grading Reports
What is a Diamond Certificate?
A diamond certificate, also known as a diamond grading report, is a detailed assessment of a diamond's characteristics performed by a professional gemological laboratory. This document serves as the diamond's identification card, verifying its authenticity and quality specifications.
Expert Tip: Always request to see a diamond's certificate when making a purchase.
It's your guarantee of the diamond's quality and helps ensure you're getting exactly what you pay for.
Major Certifying Bodies
What's Included in a Diamond Certificate?
The 4Cs
- Cut grade and proportions
- Color grade (D-Z scale)
- Clarity grade (FL-I3)
- Carat weight (to 0.001ct)
Measurements
- Length and width
- Depth percentage
- Table percentage
- Girdle thickness
Additional Features
- Fluorescence
- Polish grade
- Symmetry grade
- Plot of inclusions
Authentication
- Certificate number
- Laboratory name
- Issue date
- Security features
Understanding Different Grading Labs
GIA (Gemological Institute of America)
- Most widely respected laboratory
- Strictest grading standards
- Non-profit organization
- Invented the 4Cs grading system
- Consistent grading across all locations
EGL (European Gemological Laboratory)
- International network of labs
- More lenient grading standards
- Faster turnaround times
- Lower certification costs
- Grades smaller carat weights
Important Note: Different laboratories may have varying grading standards. A diamond with
the same specifications might receive different grades from different labs. GIA is generally considered the
most conservative and consistent in their grading.
Learn more about the characteristics graded in certificates: Cut, Clarity, Color, and Carat Weight