Certified by the World’s Trusted Laboratories
IGI — International Gemological Institute
One of the world’s largest independent gemological laboratories, IGI grades each stone’s 4Cs with state-of-the-art technology and rigorous human review.
GIA — Gemological Institute of America
The world’s foremost authority on diamond grading. GIA’s standards for cut, color, clarity and carat are the global benchmark for diamond quality.
A Certificate With Every Stone
No exceptions — every loose diamond and every finished piece ships with its official certificate and a laser-inscribed serial number you can verify online.
From Growth to Your Finger
Each diamond begins as a tiny seed crystal and grows layer by layer in a controlled laboratory — chemically, optically and physically identical to a mined diamond.
The finished stone is sent to IGI or GIA, where trained gemologists grade its cut, color, clarity and carat against strict international standards.
A microscopic serial number is laser-inscribed on the stone’s girdle — invisible to the naked eye, but a permanent link to its certificate.
The official certificate is issued and shipped with your jewelry, detailing every aspect of the stone’s quality and identity.
Search your certificate number on the laboratory’s website anytime to confirm your stone’s details — a complete, auditable record from growth to finger.
The 4Cs, Independently Measured
Cut
Proportions, symmetry and polish that determine a diamond’s brilliance — graded Excellent, Very Good, Good or Fair.
Color
Measured from D (colorless) to Z (light yellow). OENLI diamonds are available from D to H for a truly colorless, icy white look.
Clarity
The presence of internal inclusions and surface blemishes, graded on a 11-step scale from Flawless to Included.
Carat
The diamond’s weight, measured to the hundredth of a carat. We price every stone by its exact carat weight — never rounded up.
How to Check Your Certificate
- Find the laser-inscribed serial number printed on your certificate (e.g. LG123456789).
- Visit the laboratory’s website — igi.org or gia.edu — and enter the number in the certificate lookup tool.
- Confirm the 4Cs shown online match your certificate and the diamond you received. That’s your proof, forever.