IGI or GIA: which report should a lab-grown diamond have?
Either is fine for a lab-grown diamond. IGI (International Gemological Institute) grades a large share of the lab-grown diamonds sold today, and GIA (Gemological Institute of America), best known for mined diamonds, grades lab-grown ones too. Both are independent laboratories whose reports you can look up online by number. What matters more than which of the two is that the report exists, that you have checked the number yourself, and that it matches the stone.
What an independent report gives you
The laboratory examines the stone itself and records shape, weight, colour, clarity, measurements and whether it is laboratory-grown, then files that under a number you can look up. That is what lets you compare two listings honestly.
What is not a substitute
A certificate printed by the seller, a "GRA" card, or an "appraisal" that states a replacement value but no measurements. None of them is an independent examination you can verify.
How to use it on Amazon
Prefer listings that show the laboratory and the report number up front. Look the number up before buying, compare the measurements, and have an appraiser read the girdle inscription when it arrives.
Frequently Asked Questions
Are IGI grades softer than GIA grades?
Buyers and dealers often say so, especially for mined diamonds. For lab-grown diamonds the practical advice is the same: judge the stone and the measurements, not only the letters.
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