Almost every lab-grown diamond sold today arrives with a grading report from IGI or GIA. Buyers comparing stones online soon ask whether one report is worth more than the other, and whether the two labels mean different things.
The short version is that both IGI and GIA are long-established, independent laboratories, and both grade laboratory-grown diamonds to broadly comparable standards.
A diamond report is more than a document with a laboratory logo at the top. Its value lies in the independent information it provides, the ability to verify the report online, and the connection between the report and the physical diamond.
This guide explains what a diamond report does and does not tell you, what to look for when reviewing one, and how to verify the details before purchasing a lab-grown diamond.
What is a diamond grading report, and what is it not?
A grading report is an independent laboratory's written description of one specific stone. It records the diamond's carat weight, color, clarity, cut quality and measurements, and it states that the stone is laboratory-grown. It is not an appraisal, a valuation or a promise about what the diamond is worth.
The distinction matters because the two documents answer different questions. A report answers "what is this stone?"; an appraisal answers "what might it be worth?" and is usually prepared for insurance. A laboratory does not set prices, and a report that lists no value is behaving as it should.
A report is also a snapshot of the stone on the day it was examined. That is why a careful seller re-inspects each diamond against its report before it ships, rather than treating the paperwork as the final word.
What do IGI and GIA report for lab-grown diamonds?
Both laboratories grade the same core characteristics of a laboratory-grown diamond: carat weight, colour, clarity and, for round brilliants, a cut grade. Both record measurements, proportions, polish, symmetry and fluorescence, and both state that the stone is laboratory-grown. In content, the two reports cover the same ground.
Both also laser-inscribe the report number on the diamond's girdle, and both let anyone check a report number on their website.
| What it covers | IGI | GIA |
|---|---|---|
| Independent grading laboratory | Yes (International Gemological Institute) | Yes (Gemological Institute of America) |
| States that the stone is laboratory-grown | Yes | Yes |
| Carat weight, colour and clarity grades | Yes | Yes |
| Cut grade | Yes, for round brilliants | Yes, for round brilliants |
| Measurements, proportions, polish and symmetry | Yes | Yes |
| Fluorescence | Yes | Yes |
| Report number laser-inscribed on the girdle | Yes | Yes |
| Online report verification | igi.org/verify-your-report | gia.edu/report-check |
| Presence in the lab-grown market | Has historically graded a very large share of lab-grown diamonds | Issues a dedicated Laboratory-Grown Diamond Report, updated over time |
| Sold at VAALBERG | Yes | Yes |
What are the practical differences buyers notice?
In day-to-day shopping, the differences are practical rather than gemmological. The documents look different, IGI reports are more common on lab-grown listings, and each laboratory uses its own report numbering. None of these tells you anything about the quality of the stone.
Layout is the first thing people notice. Each laboratory has its own design, wording and order of information, so two reports for near-identical stones can look quite different. Once you know where to find colour, clarity, cut and the inscription number, the content lines up.
Availability is the second. Because IGI has historically handled a very large share of lab-grown grading, you will see IGI reports on more stones, including many in the 1 carat collection. GIA-graded lab-grown diamonds are also available, and VAALBERG sells stones with either report.
The third is the report number itself. IGI and GIA use different numbering, so you need to be on the right laboratory's website to verify a stone. Every VAALBERG product page shows the report number, links to the report, and includes a "Verify on IGI/GIA" link to the correct place.
Is IGI or GIA better for lab-grown diamonds?
This is the question most buyers ask, and it is the wrong one. Both laboratories are independent, both grade the same characteristics, and their standards are broadly comparable. What matters is the specific report in front of you, whether it can be verified online, and whether the stone matches it.
Claims that one laboratory is "stricter" or grades a step higher or lower circulate widely, but they are not something you can act on. Grading involves trained human judgement within defined standards, and no report tells you where within a grade a stone sits.
A better habit is to treat the report as the starting point and add two checks. First, verify the report number on the laboratory's website and confirm that grades, weight and measurements match the listing. Second, ask whether the seller has looked at the actual stone.
That second check is where VAALBERG adds something a report alone cannot. Every diamond is inspected by the team in Sweden before it ships, checked against its certificate and photographed, so that the stone you receive is the stone the report describes.
Prices follow the same logic. VAALBERG's prices include VAT, the certificate and insured shipping, so what you pay reflects the stone's grades and cut rather than a premium for a laboratory's name. You can compare IGI and GIA stones side by side in the diamond search.
How do you read the key lines of a report?
A report can look dense, but the lines that decide how a stone looks and what it costs are few. Read the grades, check the measurements, then find the inscription number and the laboratory-grown statement. The rest is supporting detail.
- Carat weight. The stone's weight to two decimal places. Read it together with the measurements, because two stones of the same weight can differ in face-up size.
- Colour. Graded on a scale that starts at D (colourless) and moves down the alphabet as tint increases. VAALBERG's Signature tier is D–E, Reserve is F and Classic is G–H, all of which look white to most eyes once set.
- Clarity. Describes inclusions and blemishes seen under magnification, from Flawless down through VVS, VS and SI. VAALBERG's Classic tier uses SI, Reserve uses VS and Signature uses VVS.
- Cut grade. Issued for round brilliants, with Excellent and Very Good at the top of the scale. For other shapes, rely on polish, symmetry, proportions and, above all, the photographs and video. Browse round diamonds to see how cut grades appear on real listings.
- Measurements, proportions, polish and symmetry. Length, width and depth in millimetres, depth and table percentages, and the finish of the facets. Together they tell you how large the stone looks and how well it is likely to handle light.
- Fluorescence. Noted as None, Faint, Medium, Strong or Very Strong. Where it is present, it is not a fault and is rarely noticeable in normal lighting.
- Inscription. The report number lasered onto the girdle, visible under a loupe. This is the physical link between the paper and the stone.
- Laboratory-grown statement and growth method. The report states that the diamond is laboratory-grown, and typically records the growth method (HPHT or CVD) and whether any post-growth treatment was detected. Neither method is a quality grade; both produce genuine diamonds.
What are the red flags to look out for?
When buying a lab-grown diamond, transparency matters. A few simple checks can help you make sure the diamond you are considering is properly documented and independently graded.
- No independent diamond report
A lab-grown diamond sold with specific grades for carat weight, color, clarity and cut should come with an independent report from a recognized gemological laboratory. The report should clearly state the laboratory that issued it and include a unique report number that can be verified online.
- A certificate issued by the seller
Some sellers provide their own certificates or grading documents. While these may contain useful information, they represent the seller's own assessment and are not an independent third-party evaluation.
An independent report from a recognized laboratory provides an additional level of transparency, allowing the information to be checked directly with the laboratory.
- A report number that cannot be verified
A genuine laboratory report should be verifiable through the issuing laboratory's online database. Check that the report number corresponds to the diamond you are considering, including its carat weight, measurements and grading details.
If the information does not match, or the report number cannot be found, it is worth asking the seller for clarification before making a purchase.
- No visible report number on the diamond
IGI and GIA reports include a report number that is typically laser-inscribed on the diamond's girdle. This inscription can be checked by a jeweller or gemologist using magnification and provides another way to connect the physical diamond with its laboratory report.
- A report with the number hidden
If a seller provides a copy of a laboratory report but deliberately hides or obscures the report number, it prevents the customer from independently verifying the document.
For a transparent buying experience, the report number should be clearly visible and easy to verify.
Frequently asked questions
Is an IGI certified lab-grown diamond less valuable than a GIA one?
No. The value of a stone comes from its weight, colour, clarity and cut, and both laboratories grade all four. Judge two stones with the same grades on the stones themselves, not on the report's letterhead.
Can I verify a VAALBERG diamond's report myself?
Yes. Every product page shows the report number, links to the report, and includes a "Verify on IGI/GIA" link to the laboratory's own checking tool. You can do this before you order and again when the stone arrives.
Does the report tell me whether the diamond is HPHT or CVD?
Reports state that the stone is laboratory-grown and typically record the growth method. Both methods produce genuine diamonds, and the method is not a quality grade. Judge the stone on its 4Cs and its appearance.
Do I need a separate appraisal for insurance?
Often, yes. A grading report describes the stone but does not state a value, and many insurers ask for an appraisal or a receipt. Your named VAALBERG expert can advise on what your insurer needs.
Does the certificate matter as much for an engagement ring as for a loose stone?
Yes, arguably more, because the centre stone is the largest part of the ring's cost. Every stone in the engagement rings range carries an IGI or GIA report, and the ring configurator pairs a specific certified stone with your setting.
