Before you spend a single rupee on a lab-grown diamond in India, there is one question that matters more than the design, more than the metal, and almost as much as the price.
Who certified this diamond?
The certificate attached to your diamond is not a formality. It is the independent record of exactly what you are buying, cut grade, colour, clarity, carat weight, and growth method, verified by a laboratory that has no financial interest in making the stone look better than it is.
In India, two names come up constantly: IGI and SGL. Every jeweller will mention at least one of them. Some will claim they are the same. Some will insist one is far superior. Neither is entirely accurate.
This guide explains what each certification body actually does, how they differ for lab-grown diamonds specifically, and which one you should prioritise when buying in India in 2026.
Why Diamond Certification Matters
A diamond certificate is not just a piece of paper. It is your protection.
Without a certificate from an independent grading laboratory, you are entirely reliant on the seller's word about the quality of the stone you are buying. Two diamonds can look identical to the naked eye but carry a 40 to 60 percent price difference based on their 4Cs grades. A certificate makes those grades verifiable, objective, and tamper-proof through the laser-inscribed report number on the diamond itself.
For a detailed look at how to read and verify a certificate, our guide on IGI Certified Lab-Grown Diamonds: What the Certificate Means and Why It Matters in India covers everything you need to know before buying.
The Two Main Certification Bodies in India
IGI: International Gemological Institute
Founded in Antwerp in 1975, the International Gemological Institute is today one of the largest independent gem grading organisations in the world. It has laboratories across Belgium, India, the USA, Hong Kong, Japan, Dubai, and several other countries.
IGI has been at the forefront of lab-grown diamond certification. As demand for lab-grown diamonds grew globally and in India, IGI developed specific grading protocols for CVD and HPHT diamonds, including clear identification of growth method on every report.
IGI has a strong physical presence in India with offices in Mumbai and other cities. A significant proportion of lab-grown diamonds sold in India, including all Goenka Jewellers diamonds, carry IGI certification.
SGL: Solitaire Gemological Laboratories
SGL is an India-based grading laboratory founded in Mumbai. It operates within the Indian domestic market and is recognised by many Indian jewellers and retailers, particularly in the mid-market and value segments.
SGL grades diamonds on the standard 4Cs system and its reports are accepted by Indian retailers and buyers. However, SGL carries limited international recognition. Its grading standards have also been perceived by some in the industry as less conservative than IGI, meaning the same stone might receive a slightly higher grade from SGL than from IGI. This is an industry-wide observation rather than a definitive criticism, but it is worth understanding as a buyer.
How They Compare: Key Differences
International Recognition
IGI is internationally recognised and accepted for resale, insurance, and export purposes globally. SGL is primarily recognised within India.
Lab-Grown Diamond Specialisation
IGI is the industry leader specifically for lab-grown diamond certification. It has the highest volume of lab-grown diamond reports globally and has invested specifically in developing its grading protocols for CVD and HPHT stones. SGL certifies lab-grown diamonds but with less developed specific protocols for lab-grown stones compared to IGI.
Grading Consistency
IGI is generally considered consistent and reliable for lab-grown diamonds, with its grading for lab-grown stones being well-regarded in the industry. SGL has a broader range of grading outcomes and is considered less conservative than IGI.
Price of Certification
SGL certificates are the more affordable of the two. IGI certificates sit in the mid-range, and that cost is built into the diamond price.
Report Verification
Both allow online verification of report numbers, and IGI has a particularly robust online verification system. Always verify the report number on the issuing laboratory's website before finalising a purchase, regardless of which certification body issued it.
Presence in India
SGL has a wide physical presence across Indian cities and is fast for turnaround in the domestic market. IGI also has strong Indian offices.
Side by Side at a Glance
Founded: IGI in 1975, SGL in Mumbai (year not publicly standardised)
Headquarters: IGI in Antwerp, SGL in Mumbai
International Recognition: IGI is high, SGL is primarily domestic
Lab-Grown Specialisation: IGI is highest, SGL is moderate
Grading Conservatism: IGI is consistent, SGL is less conservative
Price Premium: IGI is moderate, SGL is lower
Best For: IGI for lab-grown diamonds in India, SGL for domestic mid-market purchases
What This Means for Indian Lab-Grown Diamond Buyers
For the vast majority of Indian buyers purchasing lab-grown diamond jewellery, IGI is the right certification to prioritise. Here is why.
IGI has more lab-grown diamond grading experience than any other body globally. Its report format for lab-grown stones is detailed, includes the growth method, and is easy to verify online. Its international recognition means your diamond holds its documented value whether you are in Kolkata, Dubai, or London.
SGL is acceptable for domestic purchases at lower price points, particularly if budget is a primary constraint and you are buying from a reputable Indian retailer. However, for engagement rings, significant purchases, or any jewellery you may want to insure or resell internationally, IGI is strongly preferred.
Three Questions to Ask Before Accepting Any Certificate
Is the report number laser-inscribed on the diamond? Every reputable certificate from IGI or SGL includes a unique report number that is physically inscribed on the diamond's girdle. Ask to see this, or verify it under magnification at the store.
Can you verify it online right now? Pull up the IGI or SGL website on your phone and enter the report number. The full grading report should appear instantly. If the seller objects to you doing this, that is a significant red flag.
Does the report state the growth method? For lab-grown diamonds, the certificate must state whether the stone was produced by CVD or HPHT. If this information is missing from the certificate, the document is incomplete for a lab-grown stone.
A Note on Uncertified Diamonds
Some sellers in India, particularly at lower price points, offer lab-grown diamonds with no certificate at all, or with certificates from obscure or unrecognised bodies.
These should be avoided for any meaningful purchase.
Without an independent certificate from IGI or SGL, you have no verified record of the stone's quality. The seller's verbal assurance is the only thing standing between you and a stone that may be significantly lower quality than described. Given that a certified stone of the quality being claimed would not cost dramatically more, the absence of certification is itself a warning sign.
Frequently Asked Questions
1. Is IGI the best certification for lab-grown diamonds?
For lab-grown diamonds specifically, IGI is widely considered the most specialised and experienced grading body. Its dedicated lab-grown protocols and high volume of lab-grown certifications make it the preferred choice for lab-grown diamond buyers globally and in India.
2. Are SGL certified diamonds safe to buy in India?
SGL-certified diamonds are acceptable for domestic purchases from reputable retailers, particularly at lower price points. For high-value purchases, engagement rings, or jewellery intended for resale or international use, IGI certification is recommended.
3. Why are IGI certified lab-grown diamonds priced higher than SGL?
IGI carries stronger international recognition and more lab-grown grading experience, and its grading is generally considered more conservative. That consistency is what you pay for, and it is what makes an IGI report reliable for resale and insurance.
4. Can I resell an IGI certified lab-grown diamond in India?
Yes. IGI certification is widely accepted for resale, insurance, and buyback purposes in India and internationally. Goenka Jewellers backs its IGI-certified lab-grown diamond jewellery with exchange and cash buyback at 100% of the gold value and 80% of the diamond value at market rate (T&C apply).
5. What should I do if a seller offers a certificate I have never heard of?
Do not accept it as equivalent to IGI or SGL. Search the certifying body's name online, check whether it has an independent website with a report verification system, and verify what its acceptance looks like in the broader Indian market. If in doubt, ask for an IGI certificate specifically.
6. Does the certification affect the diamond's price?
Yes. SGL-certified stones are typically priced lower than IGI-certified stones of comparable grade. The certification cost is built into the diamond price by the retailer.
The Bottom Line
IGI and SGL are both real certification bodies with real grading systems. They are not interchangeable, and they are not equal for every use case.
For lab-grown diamonds in India in 2026, the choice is straightforward. IGI is the first choice for the vast majority of buyers. It is the most experienced body specifically for lab-grown stones, internationally recognised, easy to verify, and priced fairly. SGL is acceptable for domestic mid-market purchases from reputable sellers.
One rule applies regardless of which body certified your stone. Always verify the report number on the issuing laboratory's website before you hand over any money. That ten-second check is the simplest and most powerful consumer protection available to any Indian diamond buyer.
Before you buy, understand what the certificate actually tells you. Read our complete breakdown of how to read and verify your IGI certificate. Then explore Goenka Jewellers' IGI-certified lab-grown diamond collection and buy with every fact verified.