Both are legitimate. Both are rigorous. One has become the clear standard for lab grown diamonds, and the reasons why are worth understanding. A certificate isn't paperwork. It's the only part of a diamond purchase that stays with you for life.
What a diamond certificate actually is
Before we compare the two bodies, a useful frame. A diamond certificate isn't a warranty. It isn't proof of ownership. It isn't an appraisal of monetary value.
It's a forensic report. An independent laboratory examines the stone, measures it against international standards, and documents exactly what it is. Cut, colour, clarity, carat, fluorescence, origin method, any treatments. The certificate travels with the stone for the rest of its life. When the diamond changes hands in twenty years, the certificate tells the next owner what they're looking at.
This is why the certifying body matters. A certificate is only as trustworthy as the laboratory that issued it, and two labs dominate the world for lab grown diamonds.
The two names you'll encounter
GIA, the Gemological Institute of America, is the older of the two. It was founded in 1931 and it created the 4C grading system the entire industry now uses. For most of the twentieth century, a GIA certificate was the single most respected document in fine jewellery.
IGI, the International Gemological Institute, was founded in 1975 in Antwerp, the historic diamond capital of the world. Today it's the largest independent diamond grading laboratory in the world, with labs across India, the US, Belgium, Thailand, Hong Kong, Dubai, and beyond.
Both are independent. Both are non profit. Both have rigorous grading protocols. Both are considered legitimate by serious jewellers worldwide.
For lab grown diamonds specifically, though, a quiet shift has happened over the last decade. It's worth understanding why.
Why IGI became the standard for lab grown diamonds
For decades, GIA declined to grade lab grown diamonds using the same 4C system they used for natural stones. When GIA did begin grading, they used a compressed scale. Colour came in ranges like "Colourless" or "Near Colourless," not the precise D to Z scale natural diamonds received. Clarity was similar.
GIA changed this position in 2020 and now grades lab grown diamonds on the full 4C scale. By the time they made the change, IGI had already been grading lab grown diamonds on the full scale, with the same precision as natural stones, for years. Jewellers, especially those specialising in lab grown diamonds, had already built their trust and certification pipelines around IGI.
The market reality today is straightforward.
- IGI dominates lab grown certification globally, with the deepest infrastructure in India. A large share of the world's lab grown diamonds now gets cut and polished here.
- GIA handles some lab grown stones, particularly in North American markets, but their lab grown grading is newer and less granular in practice than IGI's.
- For natural diamonds, GIA remains the widely preferred standard in most parts of the world.
None of this tells you one laboratory is "better." It tells you which laboratory has built the most depth in the specific category of lab grown diamonds. For a lab grown purchase, IGI offers the more rigorous, more detailed, more current certification.
What an IGI certificate tells you
A Nivara diamond arrives with an IGI certificate that documents the following.
- The 4Cs. Carat weight, cut grade, colour grade on the full D to Z scale, clarity grade.
- Measurements. Exact dimensions in millimetres.
- Proportions. Table percentage, depth, girdle, culet.
- Polish and symmetry. Graded separately from cut.
- Fluorescence. Under ultraviolet light.
- Growth method. HPHT or CVD, documented honestly.
- Laser inscription. A unique certificate number etched onto the girdle of the diamond at microscopic scale, invisible to the eye but visible under 10x magnification.
That last detail deserves a pause. The laser inscription links your diamond and your certificate permanently. No switching. No swapping. No confusion. In twenty years, you can take your diamond to any jeweller in the world, have them read the inscription, and match it to the certificate. That's what a certified diamond actually guarantees.
What the certificate doesn't tell you
An IGI certificate doesn't tell you whether a diamond is beautiful. It doesn't tell you whether it suits the person wearing it. It doesn't tell you whether a certain cut will photograph well, or whether a particular colour will look warmer in candlelight than in daylight.
Those judgments belong to the good jeweller you choose to work with, and they're the reason we still believe in the physical showroom, the appointment, the unhurried conversation. The certificate is the floor of trust. Taste is the work above it. If you're still mapping out your first purchase, our guide to buying your first lab grown diamond covers what to expect at every step.
Questions we get asked, and honest answers
Is an IGI certified lab grown diamond worth less than a GIA certified one?
No. Not meaningfully. The certification body affects resale confidence more than resale price, and for lab grown diamonds, IGI is the more established certifier. A GIA certified lab grown diamond isn't more valuable just for being GIA certified. For current pricing by carat weight and quality, see our lab grown diamond price guide for India.
Is one certification stricter than the other?
Both are strict. Both grade on international standards. When the same stone goes to both labs, the outcomes differ rarely and usually within one grade step. For lab grown diamonds specifically, IGI's grading depth and experience is, at present, unmatched.
What if I want a GIA certificate specifically?
We can source GIA certified lab grown diamonds on request. This adds time to the process and, depending on the stone, some cost. Most of our customers, once they understand the landscape, stay with IGI. But the choice is always yours. At Nivara, we don't build around a lab. We build around you.
How do I verify my certificate is genuine?
Every IGI certificate has a unique number. Visit IGI's official website, enter the certificate number, and the full report loads. The laser inscription on the diamond's girdle must match. If both match, the diamond is genuine and exactly as described.
The shorter version
Both IGI and GIA are legitimate. For lab grown diamonds, IGI offers the deeper infrastructure, the more detailed grading protocols, and the longer history of lab grown expertise. Every Nivara diamond carries IGI certification because we believe our customers deserve the most rigorous current standard, not a legacy one.
A diamond is a lifetime object. The certificate that accompanies it should be too.
Come see the difference in person
A certificate in a photograph is just paper. A certificate alongside the diamond it documents, in your hand, in warm light, with an honest conversation around it, is something else entirely. That's what our showrooms are for.
Book a private viewing at our Hyderabad, Bangalore, or Indore showroom. Or start a conversation on WhatsApp. We'll walk you through certificate samples and answer anything.
At Nivara, transparency isn't a marketing word. It's the floor we build everything else on.
