An IGI report stops looking like jargon the moment you know which four lines matter. Here is how to read a lab-grown diamond report end to end, and the two-minute check that confirms your stone is exactly what you paid for.
An IGI lab-grown diamond report tells you four things that matter: that the stone is laboratory-grown, its 4Cs (cut, colour, clarity, carat), its growth method (HPHT or CVD), and a unique report number laser-inscribed on the diamond itself. To trust it, match the number on the paper to the inscription on the stone, then look that number up on IGI's official database. That is the whole skill, and you can learn it in the time it takes to finish this read.
- An IGI report is a neutral description of your diamond, written by a lab, not the seller. It is not a price valuation.
- The four lines to read: the laboratory-grown statement, the 4Cs, the growth method, and the report number.
- Two checks prove it is real: the inscription on the girdle must match the paper, and the number must verify on IGI's site.
- HPHT and CVD are growth methods, not quality grades. Both make real, chemically identical diamonds.
- Tiny accent stones often have no individual report, and that is normal. For a single solitaire-style stone, expect one.
What a grading report is, and why it matters
A diamond grading report is an independent description of a stone, written by a gemological lab rather than the shop selling it. It is not a valuation and it does not set a price. It is a neutral record of what the diamond is, so you buy a known quantity instead of taking anyone's word for it. With lab-grown diamonds especially, where you cannot tell a grown stone from a mined one by eye, the report is your proof of exactly what you hold.
IGI, the International Gemological Institute, grades the large majority of the world's lab-grown diamonds and is the report you will most often see in India. Labels vary a little from lab to lab, but the lines you need to read sit in the same places everywhere. You can see how a lab frames the science on the IGI education pages.
A report does not tell you what a diamond is worth. It tells you what it is, so two stones can be compared honestly on the same scale.
The four lines that actually matter
Open any IGI report and your eye only needs to find four things. The rest is context.
1. The laboratory-grown statement
Near the top, a line states the stone is laboratory-grown, usually worded as Laboratory-Grown Diamond or Man-Made. This single line confirms the category of what you are buying. On a lab-grown report it is always present and always explicit, never buried.
2. The 4Cs
Below the header sit the four grades that describe the diamond. Carat weight is the measured weight. Colour is a letter grade from D, the most colourless, running down the alphabet as warmth increases. Clarity runs from Flawless through VVS, VS, SI and below, describing internal characteristics. Cut, for round brilliants, is graded Excellent through Poor, and it is the grade that most affects sparkle. For fancy shapes such as ovals and pears, you will see separate polish and symmetry grades instead of one overall cut grade. If you want the textbook version of each scale, the GIA 4Cs explainer is the standard reference.
3. The growth method
One line is unique to lab-grown reports: how the diamond was made, either HPHT (high pressure, high temperature) or CVD (chemical vapour deposition). Both produce real, chemically identical diamonds, so this is a record of method, not a ranking of quality. Knowing it is there means the term will not throw you when a jeweller mentions it.
4. The report number
Every report carries a unique number, printed near the top with the date. That same number is laser-inscribed on the diamond, and it is the thread that ties the paper to the physical stone. Hold on to it. It is what you type into IGI's site to verify.
A field-by-field map
Here is each line you will meet on the report and what it actually means in plain terms.
| Field on the report | What it means |
|---|---|
| Report number and date | The unique ID for this stone and when it was graded. Match it to the inscription and verify it online. |
| Shape and cutting style | The outline (round, oval, pear) and faceting style of the diamond. |
| Measurements | The stone's dimensions in millimetres. Useful for confirming a setting will fit. |
| Laboratory-grown / Man-Made | Confirms the stone is grown, not mined. |
| Carat weight | The measured weight of the diamond. |
| Colour grade | D (most colourless) downward as warmth increases. |
| Clarity grade | Flawless down through VVS, VS, SI, describing internal characteristics. |
| Cut grade (or polish + symmetry) | How well the stone is cut. The biggest driver of sparkle. |
| Growth method | HPHT or CVD. A record of how it was grown, not a quality ranking. |
| Inscription | The report number micro-engraved on the girdle for verification. |
The two checks that prove it is real
A report is only as good as your verification of it, and there are exactly two steps. Run both on any meaningful purchase.
- Match the inscription. Most IGI-graded lab-grown diamonds have their report number, and often the words Lab Grown, micro-inscribed on the girdle, the thin band around the stone's widest point. A jeweller can show you this under a loupe or microscope. Confirm the inscribed number matches the number printed on the report.
- Verify online. Go to IGI's official website, enter the report number into their report-check tool, and confirm the details on screen match both the paper and the stone. It costs nothing, takes about a minute, and it is the step that separates a genuine report from a photocopy.
If a number on the paper does not match the engraving on the girdle, or does not appear in IGI's database, stop and ask questions before you pay.
Do and don't, when a report lands in your hand
- Do match the report number to the laser inscription on the girdle under magnification.
- Do verify the number on IGI's official site yourself, not just the seller's screenshot.
- Do read the cut grade closely. It shapes sparkle more than a colour grade you cannot see with the naked eye.
- Don't treat HPHT or CVD as better or worse. Judge the diamond on its 4Cs.
- Don't read the report as a price tag. It describes the stone, it does not value it.
- Don't expect an individual report on a tiny accent or melee stone. That is normal below a certain size.
What this means when you buy in India
A practical note for buying here. Always ask whether a lab-grown diamond comes with its own IGI report and whether the stone is laser-inscribed. For studs and small pendant diamonds below a certain size, individual reports are less common, and that is normal: grading a tiny stone costs more than the stone is worth. For a single solitaire-style necklace or a stone you can name on its own, a report and an inscription you can verify is reasonable to expect.
As a rough sense of scale, IGI report verification itself is free online, so the cost of grading is already built into a stone that arrives with its own report rather than something you pay extra for at the counter. When you compare two stones in your budget, say two solitaire-style necklaces around the same price, the report is what lets you see why one is graded higher than the other. If you are still weighing the bigger question of value, my guide to whether lab-grown diamonds are worth it walks through the price gap and the everyday logic.
When you are ready to see how this reads on real designs, our Astris Pear Necklace and the wider necklaces collection are a good place to put the 4Cs into context, and an everyday ring like the Aligned Constellation Ring shows how cut and clarity translate into daily sparkle.
FAQs
What does an IGI report tell you?
An IGI lab-grown diamond report states that the stone is laboratory-grown, its 4Cs (cut, colour, clarity and carat), its growth method (HPHT or CVD), its measurements, and a unique report number that is laser-inscribed on the diamond's girdle for verification.
How do I verify a lab-grown diamond report?
Two steps. Check that the report number laser-inscribed on the diamond's girdle matches the number on the paper report, viewable under magnification. Then enter that number into IGI's official online report-check tool and confirm the details match. It is free and takes about a minute.
Does HPHT or CVD mean a better diamond?
Neither. HPHT and CVD are simply two methods of growing a diamond, and both produce real, chemically identical stones. The growth-method line is a record, not a quality ranking. Judge the diamond on its 4Cs, and on the cut grade most of all.
Do small everyday diamonds come with a report?
Often not individually. Grading a tiny accent or small stud diamond costs more than the stone is worth, so individual reports are uncommon below a certain size, which is normal. For a single solitaire-style stone, expect a verifiable IGI report and inscription.
Is an IGI report the same as a valuation?
No. A report describes the diamond's qualities so you know what you have. It does not set a price or appraise the design. Pricing depends on the 4Cs together, the metal, and the design, which is a separate question from what the report records.
The short version
Read four lines, run two checks, and an IGI report turns from jargon into a tool you control. It confirms the stone is what was promised and lets you compare two diamonds honestly on the same scale. Once that is second nature, you are buying with open eyes, whether you start with a single solitaire-style necklace or a ring you will reach for every day.