What Does IGI Certified Mean? How to Read the Report
Quick answer
IGI certified means a diamond has been graded by the International Gemological Institute, an independent lab founded in 1975. An IGI report for a lab grown diamond lists its carat weight, color, clarity and cut, states that it is laboratory grown, and can note how it was grown, CVD or HPHT. In 2024 IGI graded about 65% of the world's lab grown diamonds. An IGI report gives a lab grown diamond full color and clarity grades, so you can see exactly where your stone falls.
| IGI report | At a glance |
|---|---|
| Grading | Full 4Cs: color, clarity, cut, carat |
| Origin | States "laboratory grown" |
| Growth method | CVD or HPHT can be noted |
| Check it | Report number on IGI's website |
| Founded | 1975, Antwerp |
| Share of lab grown grading | About 65% (2024) |
IGI, JCK (August 2024) and Blackstone (2023).
In this guide
What is IGI?
The International Gemological Institute (IGI) is an independent gem grading lab, founded in Antwerp in 1975, according to Blackstone, with labs around the world. It began grading lab grown diamonds in 2005, according to IGI, earlier than most labs. In 2024 it graded about 65% of lab grown diamonds, according to IGI's IPO filing as reported by JCK.
What an IGI lab grown diamond report shows
- Carat weight of the diamond.
- Color and clarity grades on the same scales used for mined diamonds, such as F color, VS1 clarity.
- Cut grade for round brilliants, plus polish and symmetry.
- Measurements and proportions in millimeters.
- Origin: a clear statement that the diamond is laboratory grown. The growth method, HPHT (high pressure, high temperature) or CVD (chemical vapor deposition), and any post-growth treatment can also be noted.
- A report number you can look up on IGI's website. Many diamonds also carry the number laser inscribed on the girdle.
An IGI diamond report grades a single loose diamond and tells you exactly what stone is in your ring. An IGI jewelry report covers a finished piece with many small diamonds, such as a tennis bracelet, and records their total carat weight, color and clarity.
Why IGI for lab grown diamonds
IGI grades lab grown diamonds on the full 4Cs, using the same color and clarity scales as mined diamonds. If you want to see exactly where a stone falls, say G color and VS2 clarity, an IGI report gives you that detail. It's also the most widely used lab for lab grown diamonds: it graded about 65% of them in 2024, according to IGI's IPO filing as reported by JCK.
Is IGI a good certification?
For lab grown diamonds, yes: it's the most widely used independent lab, it gives full color and clarity grades, and its reports can be checked online. Like any lab's grades, IGI's are an expert opinion, so judge the stone with your eyes too: look at photos and video of the exact diamond and check that it looks bright and clean.
One thing an IGI report is not: a price guarantee or an appraisal. It describes the diamond; it doesn't value it.
How to read and check a report
- Match the number. Enter the report number on IGI's website and check the details match your paperwork.
- Check carat and measurements against what you ordered.
- Look for "laboratory grown". A lab grown diamond's report says so clearly, and the FTC requires sellers to disclose it.
- Read any growth method or treatment note.
Our lab grown diamonds and IGI
Every lab grown engagement ring we make has an IGI report for its center diamond, E to G color and VVS to VS clarity. Lab grown stud earrings from 1 ct tw (0.5 carat or more per diamond) come with an IGI report for each diamond too. Smaller studs and tennis bracelets, with their many small diamonds, come with an IGI jewelry report that records the total carat weight, color and clarity of the finished piece. Every piece also comes with an Estara certificate.
Our moissanite is graded to our own standard, D colorless and VVS, and comes with an Estara certificate. IGI reports are for our lab grown diamonds only, so you always know which stone you're buying.
IGI-graded lab grown diamonds
All lab grown diamonds
Classic Bond Round, lab grown diamondFrom $389 silver · $789 14KView ring
Classic Bond Oval, lab grown diamondFrom $389 silver · $769 14KView ring
The One, design your ownFrom $449 silver · $999 14KView ring
Classic Solitaire StudsFrom $159 silver · $269 14KView earrings
Certified, Every Piece
Estara certificate, plus IGI on lab grown
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Tracked to your door
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FAQs
What does IGI certified mean?
It means the diamond was graded by the International Gemological Institute, an independent lab. The report lists carat, color, clarity and cut, and for a lab grown diamond it states that the stone is laboratory grown.
Is IGI a good lab for lab grown diamonds?
Yes. IGI is the most widely used lab for lab grown diamonds and gives full color and clarity grades, so you can see exactly where your stone falls.
Are IGI certified diamonds real?
Yes. IGI grades real diamonds, both mined and lab grown, and the report states which one it is. A lab grown diamond is real diamond made in a lab.
Can I check an IGI report online?
Yes. Enter the report number on IGI's website to see the grading details. Many diamonds also have the number laser inscribed on the girdle.
Do all lab grown diamonds come with an IGI report?
Ours do. At House of Estara, every lab grown engagement ring center and every stud pair from 1 ct tw has its own IGI report, and smaller pieces and tennis bracelets have an IGI jewelry report for the finished piece. Every piece also comes with an Estara certificate.
Is moissanite IGI certified?
We don't sell moissanite with IGI reports. Our moissanite is D colorless, VVS, and comes with an Estara certificate.
Lab grown diamonds with an IGI report
Engagement rings from 1 to 5 carats and studs, every piece IGI certified.
Shop lab grown diamond ringsShop lab grown studsRelated guides
Sources
- IGI, Lab Grown Diamond Report.
- JCK, IGI initial public offering, August 26, 2024.
- Blackstone, Blackstone acquires IGI, May 21, 2023.
Some images in this guide are AI-generated illustrations, not photos of specific House of Estara pieces.
