Alexis by Best Brilliance, shown in 14K white gold with an emerald-cut lab-grown diamond. Explore the ring.
IGI is an established, widely used laboratory for lab-grown diamond reports. At Best Brilliance, most diamonds we sell come with IGI reports; we also offer a smaller selection with GIA documentation. IGI’s broad acceptance in the lab-grown market and its detailed grading information are why we use its reports for most of our lab-grown selection. But the report is a starting point: choosing a diamond also calls for an individual gemological assessment of the actual stone.
For colorless to near-colorless lab-grown diamonds, IGI grading reports and GIA’s current Quality Assessment present quality differently. That is the comparison covered here. Natural diamonds and colored lab-grown diamonds have separate reporting services.
Why IGI is an established choice for lab-grown diamonds
IGI’s role in lab-grown grading is supported by its scale in that market. Its April 2025 investor presentation, citing Redseer industry research, reported approximately 65% of worldwide laboratory-grown diamond certifications by number for calendar year 2023. That is a dated measure of market adoption, not a claim about an exact market share today or a guarantee about any individual diamond.
For shoppers, IGI’s individual grades and measurements provide a useful basis for comparing lab-grown diamonds. GIA also provides independent laboratory services, but its current reporting format for colorless to near-colorless lab-grown stones differs. The practical question is what the specific document tells you about the diamond you are considering.
What does an IGI report tell you?
IGI's laboratory-grown diamond reports identify origin and document characteristics such as measurements and the 4Cs. Check the specific report type: an assessment of mounted jewelry is subject to what the setting allows the laboratory to examine. Growth-method and treatment information can appear in the comments; do not assume every document includes identical detail. IGI explains its reports and verification service.
What changed at GIA?
Introduced on October 1, 2025, GIA's Laboratory-Grown Diamond Quality Assessment uses the overall descriptions Premium and Standard, based on its criteria for color, clarity and cut. The current service is for loose, colorless to near-colorless lab-grown diamonds weighing at least 0.15 carat. Stones below the minimum criteria for Standard do not receive that assessment. This replaced GIA's previous service for D-to-Z lab-grown diamonds; it is not a change to natural-diamond grading. See GIA's service announcement.
GIA also offers separate reports for colored lab-grown diamonds. Check GIA’s current service descriptions for the applicable scope.
Older GIA documents can look different from current assessments. Check the document's date and service name before comparing it with another report. A different format alone does not prove that a document is invalid.
| Question | IGI | Current GIA Quality Assessment for colorless to near-colorless lab-grown diamonds |
|---|---|---|
| How is quality presented? | Individual characteristics and grades in the applicable report format | An overall Premium or Standard assessment |
| What should I check first? | Report type, number and the stone's listed details | Assessment type, number, date and listed details |
| Can I directly translate between the two? | Do not treat an overall category as a substitute for a complete set of individual grades. | |
Read the report alongside the product page
Start with the stone you intend to buy, not the laboratory logo. Open the product specifications and the report side by side. Confirm that both describe a laboratory-grown diamond and that the shape, measurements and weight are consistent.
Check whether a ring's advertised carat weight refers to its center stone or to all diamonds combined. A report for one diamond does not automatically describe every accent stone or the finished setting. If a page offers several size options, ask which report corresponds to your selected configuration.
Next, ask for a useful visual comparison. A report is documentation; a video helps you decide whether you like the stone's appearance. Record your unanswered questions before moving to checkout, especially if the listing shows a representative image instead of the exact diamond.
Verify the document, then match it to the stone
- Obtain the report or assessment number and a readable copy of the document.
- Use the issuing laboratory's official verification service, rather than relying only on an image supplied by a seller.
- Compare the returned details with the document and the product specifications.
- Ask the jeweler how the stone is matched to its report, including any inscription and its visibility in the setting.
- Keep the report with your receipt and the final order specifications.
A valid online record confirms that a record exists. It does not, by itself, establish that the physical diamond in front of you is the same stone. If details conflict, resolve them before completing the purchase.
Look beyond the grades: assess the individual diamond
A grading report is important, but it does not replace examining the particular diamond. Laboratory grading already involves gemological examination under controlled conditions. A further assessment for your purchase connects that information to the stone’s actual appearance, condition and suitability for the ring. Two diamonds with similar headline grades can still look different.
A qualified gemologist can help assess the stone’s proportions and face-up dimensions, visible color and transparency, the position and visibility of inclusions, and how its facets handle light. These observations should be considered together, rather than reducing the decision to a single grade. GIA explains why viewing conditions affect a diamond’s appearance.
Review the exact diamond in more than one lighting environment where possible, not only under strong spotlights. An exact-stone video can help with an initial comparison, but camera settings and lighting influence what you see; a representative product image cannot establish the condition or appearance of your individual stone. Ask which checks were performed physically, which relied on images or video, and whether the stone was loose or mounted.
What a report does not promise
Do not use a laboratory name as a shortcut for guaranteed resale value, an automatic price premium or a fixed “grade adjustment” between laboratories. A report is also not a promise that you will prefer one diamond over another.
For a ring you plan to wear, compare the whole purchase: the actual stone, setting, workmanship, fit and service terms. Read our shipping, returns and repairs policy for the conditions that apply. Eligibility can depend on the item and any customization.
Common questions
Is an IGI report enough to choose a lab-grown diamond?
It is an important source of independent grading information, but it should be considered alongside an individual assessment of the diamond. Match the report to the stone, compare its actual appearance and ask about any checks that cannot be established from the document alone.
Should I reject an older GIA report?
Not because of its format alone. Verify it through GIA and confirm that it matches the diamond being offered. Ask the jeweler to explain which service produced it.
Is Premium a direct replacement for a specific IGI grade?
No. An overall assessment and a set of individual grades convey different information. Ask what evidence supports the particular comparison you are making.
How can Best Brilliance help?
Send our team the rings you are considering and ask for the report details for each selected stone. Contact Best Brilliance to compare the documents, dimensions and setting options before choosing.