Diamond Certifications
Every diamond we sell comes with independent certification from the world's most trusted gemological laboratories. Know exactly what you're buying.
Our Certification Promise
All diamonds 0.30 carats and above at 6ixofDiamonds come with GIA certification. This ensures you receive an unbiased, expert assessment of your diamond's quality. Smaller accent diamonds are carefully selected to meet our strict quality standards.
Trusted Laboratories
We work with the world's leading gemological laboratories to ensure every diamond meets the highest standards.
Gemological Institute of America
The most respected and widely recognized diamond grading laboratory in the world. GIA created the 4Cs grading system.
- Created the universal 4Cs grading standard
- Strictest and most consistent grading
- Laser inscription on diamond girdle
- Online verification available
American Gem Society
Known for the most scientific cut grading system. AGS uses a 0-10 scale where 0 represents the ideal.
- Most advanced cut grading system
- Light performance analysis
- Ideal cut certification
- Consumer protection focus
International Gemological Institute
One of the largest independent gemological laboratories with locations worldwide.
- Global presence and recognition
- Fast turnaround times
- Comprehensive grading reports
- Lab-grown diamond expertise
Understanding the 4Cs
The universal standard for assessing diamond quality, created by GIA.
Cut
The most important factor for brilliance. Cut determines how well a diamond reflects light.
- Excellent
- Very Good
- Good
- Fair
- Poor
Color
Measures the absence of color. The less color, the higher the grade.
- D-F (Colorless)
- G-J (Near Colorless)
- K-M (Faint)
- N-Z (Light)
Clarity
Measures the absence of inclusions and blemishes.
- FL/IF (Flawless)
- VVS1-VVS2
- VS1-VS2
- SI1-SI2
- I1-I3
Carat
The weight of the diamond. One carat equals 200 milligrams.
- Weight measurement
- Not a size indicator
- Price increases exponentially
How to Verify Your Certificate
Find Your Report Number
Locate the report number on your certificate. This unique identifier is also laser-inscribed on the diamond's girdle.
Visit the Lab Website
Go to the official website of the grading laboratory (GIA, AGS, or IGI) and find their report verification tool.
Enter Your Report Number
Input your certificate number to retrieve the official grading report and verify all specifications.
Compare & Confirm
Compare the online report with your physical certificate and diamond to ensure everything matches.
Questions About Certifications?
Our diamond experts are happy to explain certifications and help you understand exactly what you're purchasing.