8 Reasons Why Ouros Jewels Uses IGI Certification for Every Lab Grown Diamond

Every lab grown diamond at Ouros Jewels ships with an IGI certificate because IGI is the only major grading body that still issues full 4Cs reports for lab grown stones in 2026, holds ISO 17025 accreditation for that specific category, and commands roughly 65% of the global lab grown diamond certification market. For a buyer, that combination means the grade on the paper is independently verifiable, the methodology is internationally standardized, and the report carries weight whether you’re insuring the ring or reselling the stone years later.

There is also a practical timing reason. In October 2025, GIA replaced its detailed 4Cs grading for lab grown diamonds with a simplified two-tier system that labels stones either “Premium” or “Standard.” That change removed the granular color and clarity data buyers need to compare stones side by side. IGI did not follow suit. The eight reasons below explain why that distinction, and several others, made IGI the clear choice for every stone Ouros Jewels sells.

Why does IGI still issue full 4Cs grades when GIA stopped?

IGI publicly reaffirmed its commitment to the full 4Cs scale for lab grown diamonds after GIA’s October 2025 shift. That means every IGI report still assigns a specific grade on the D-to-Z color scale and the FL-to-I3 clarity scale, exactly as it would for a natural diamond.

The practical effect for a buyer is significant. When you see “E color, VVS2 clarity” on an IGI certificate, you can compare that stone directly against any other IGI-certified stone. A GIA report issued after October 2025 tells you only “Premium” or “Standard,” which gives you no way to know whether the stone is D color or H color, or whether the clarity is IF or SI1. For anyone trying to make an apples-to-apples comparison between two stones, IGI’s continued use of the 4Cs is not a minor technical footnote. It is the entire basis for the comparison.

Does IGI have the experience to grade lab grown diamonds accurately?

IGI began grading gem-quality lab grown diamonds in 2005, years before most other institutions had developed specific protocols for synthetic stones. That early start matters because grading lab grown diamonds is not identical to grading mined ones. Growth method, post-growth treatment, and origin identification each require different analytical tools and institutional knowledge built over time.

By 2026, IGI holds roughly 65% of the global lab grown diamond certification market. That volume is not just a commercial statistic. It means IGI gemologists grade more lab grown stones per year than any other lab, which keeps their calibration current and their reference sets large. Ouros Jewels benefits from that depth directly: every stone we certify goes through a grading process shaped by two decades of lab grown diamond-specific data.

What makes an IGI report independently verifiable?

IGI holds ISO 17025 accreditation for both natural and lab grown diamond grading. ISO 17025 is the international standard for testing and calibration laboratories. It covers measurement traceability, equipment calibration, and procedural consistency. IGI became the first laboratory in the world to hold this accreditation specifically for lab grown diamonds.

Beyond the accreditation, every IGI-certified lab grown diamond receives a laser inscription on the girdle of the stone. That inscription includes the report number and the words “LAB GROWN,” etched microscopically and readable under a 10x jeweler’s loupe. The inscription links the physical diamond to its paper record, making it straightforward to confirm that the stone in the ring matches the certificate in your hand. You can also enter the report number at igi.org to pull the full grading record online, at no cost.

How does the grading process itself protect the buyer?

IGI’s grading is anonymous by design. When a stone arrives at the lab, it receives an auto-generated identification number. Multiple graders then submit color and clarity opinions independently, with no collaboration between them. The final grade is determined only when enough graders agree. Color is assessed in a standardized viewing environment with the diamond placed upside down to prevent the setting or shape from influencing the reading. Clarity is evaluated at 10x magnification.

That structure is designed to remove the kind of grade inflation that can occur when a single grader knows who submitted the stone. For a buyer purchasing from Ouros Jewels, it means the grade on the report was not assigned by us. It was assigned by a third party following a documented, multi-step process that IGI describes as 14 discrete stages from intake to final report.

Why does IGI certification matter for insurance and resale?

Insurers and appraisers work from documentation. An IGI certificate gives them a specific carat weight, cut grade, color grade, clarity grade, and growth method in a format they recognize. With 31 laboratories across 10 countries, IGI reports are accepted by jewelers, insurers, and buyers in every major market. That geographic reach means the certificate travels with the stone regardless of where the owner eventually takes it.

The resale market for lab grown diamonds is still developing, and pricing is driven primarily by the stone’s documented specifications rather than by brand sentiment. A certificate that states “E color, VVS1 clarity, Excellent cut” gives a secondary buyer something concrete to price against. A certificate that says “Premium” does not.

Does IGI disclose the growth method on every report?

Yes. Every IGI lab grown diamond report explicitly states whether the stone was grown via CVD (Chemical Vapor Deposition) or HPHT (High Pressure High Temperature). It also states the origin as “Laboratory-Grown,” distinguishing the stone from natural diamonds and from simulants like moissanite.

This matters because some buyers have a preference for one growth method over the other, and some stones undergo post-growth HPHT treatment to improve color. When that treatment has been applied, the IGI report notes it. Ouros Jewels does not select stones based on growth method alone, but we do require that every stone’s method and any treatment be disclosed on the certificate. A buyer who wants to know exactly how their diamond was made can find that answer on the IGI report without having to ask us.

IGI Certification Is the Right Choice for Lab Grown Diamond Buyers

The case for IGI comes down to specificity. Full 4Cs grading and ISO 17025 accreditation together give a buyer a grading record that holds up under scrutiny: a jeweler appraising the stone for insurance can price it to the exact color and clarity grade, and a resale buyer can verify the report number at igi.org in under a minute before committing to a purchase.

Ouros Jewels reviews every stone against IGI’s grading criteria before it enters our inventory. That process is why we work exclusively with IGI rather than accepting non-certified stones or reports that no longer carry granular 4Cs data. Before buying any certified lab grown diamond, enter the report number at igi.org to confirm the grade is current and matches the stone you are being offered.

Frequently Asked Questions

Is IGI certification better than GIA for lab grown diamonds in 2026?

For lab grown diamonds specifically, IGI is the more practical choice in 2026. GIA replaced its full 4Cs grading for lab grown stones with a two-tier “Premium or Standard” system in October 2025, removing the granular color and clarity grades buyers use to compare stones. IGI continues to issue complete 4Cs reports, making stone-to-stone comparison straightforward.

Can I verify my IGI certificate before my Ouros Jewels order ships?

Yes. Every IGI certificate carries a unique report number that can be entered at igi.org to retrieve the full grading record, including color, clarity, cut, carat weight, growth method, and any treatments. Ouros Jewels provides the certificate details with your order so you can verify the report independently before the piece arrives.

What does the laser inscription on an IGI-certified diamond actually say?

The inscription is etched microscopically on the girdle of the stone and includes the IGI report number along with the words “LAB GROWN.” It is permanent, visible under a 10x jeweler’s loupe, and links the physical diamond to its grading record. Any mismatch between the inscription and the printed certificate is a red flag worth investigating before accepting a stone.

Does IGI certification affect the resale value of a lab grown diamond?

IGI certification documents the stone’s specifications in a format recognized by insurers, appraisers, and secondary-market buyers in most major markets. Because lab grown diamond resale pricing is driven by documented quality rather than brand sentiment, a certificate with specific color, clarity, and cut grades gives a buyer something concrete to price against. A simplified “Premium or Standard” designation from another lab provides less pricing information.

Why does Ouros Jewels not offer non-certified or GIA-certified lab grown diamonds?

Ouros Jewels uses IGI exclusively because it provides the most complete and verifiable grading report for lab grown diamonds available today. Non-certified stones offer no independent quality verification at all. GIA-certified lab grown stones issued after October 2025 no longer carry granular 4Cs grades, which limits a buyer’s ability to compare quality or document the stone for insurance purposes with full specificity.