How to Read a Lab-Grown Diamond Certificate

Start at the top of the document and confirm three things: 1. Who issued the report? For example, IGI or GIA. 2. What type of document is it? It might be an individual loose-diamond report, a finished-jewellery report or a current GIA Laboratory-Grown Diamond Quality Assessment. 3. Does it explicitly identify the stone as laboratory-grown? Never assume origin simply from the logo or the word "diamond".

After that, work through the report number, issue date, shape, measurements, carat weight and relevant quality information.

Then inspect additional information such as fluorescence, proportions, clarity characteristics, laser inscription, growth-method comments and treatment disclosure where provided.

Finally, verify the report number through the issuing laboratory's official online verification service.

The most important principle is simple: Read the report that is actually in front of you rather than applying one generic diamond-certificate template to every laboratory.

Consumers frequently use the phrases diamond certificate and certified diamond. Gemmological laboratories may use more precise terminology.

GIA explicitly states that it does not "certify" diamonds. It examines them and issues reports or assessments containing technical information.

A laboratory report is also not automatically an appraisal, warranty or guarantee.

So although this article uses "certificate" because that is how many consumers search for the information, the actual document should normally be described using the issuing laboratory's terminology.

For the broader question of whether a diamond needs such documentation, see Do Lab-Grown Diamonds Need Certification?

The first thing to read is the laboratory name. Do not begin with colour or clarity. The laboratory matters because grading systems, reporting terminology and available fields can differ.

Two documents may both relate to laboratory-grown diamonds but not be directly interchangeable.

For example: IGI currently provides detailed laboratory-grown diamond reports with individual quality information. GIA currently uses a separate Laboratory-Grown Diamond Quality Assessment for qualifying colourless-to-near-colourless laboratory-grown diamonds. Other laboratories may use still different report designs.

This is why advice such as: "Look for VS1 in the clarity box on every lab-grown certificate" is unreliable. That box may not even exist in the same form on another report type.

Next, read the document title. This is essential.

An individual loose-diamond report is different from a finished-jewellery report. A GIA Laboratory-Grown Diamond Quality Assessment is different from an older GIA Laboratory-Grown Diamond Report. A fancy-coloured-diamond report can also contain different information from a report for a colourless diamond.

Before interpreting any grade, determine exactly what service produced the document.

Suppose one document covers a loose 1.50 ct centre diamond. The laboratory can examine that diamond independently before it is mounted.

Now suppose another report covers a completed tennis bracelet containing 50 mounted diamonds. The second document is evaluating a jewellery article under very different physical conditions. Settings can obscure portions of stones and prevent each mounted diamond from being weighed independently. The information available therefore differs.

For the full distinction, read Diamond Certification vs Jewellery Certification.

A laboratory report normally has a unique identifying number. This is one of the most useful fields on the entire document because it allows you to connect the paper or digital report with the laboratory's archived record.

Do not treat the report number as decorative text. Use it.

Where the laboratory provides an official report-verification service, enter the number there and compare the retrieved information with the document you received.

Important: Illustrative report number. For the worked examples in this article, we will use: EXAMPLE-ONLY-001. This is an illustrative identifier created only for this educational guide. It is not a genuine IGI, GIA or other laboratory report number and should not be entered into a laboratory verification system.

Never publish a realistic-looking invented report number without making this distinction clear.

Reports normally include an issue date. This can help distinguish documents and provide context about which reporting system was in use when the diamond was examined.

That matters particularly for GIA laboratory-grown diamonds because GIA changed its standard colourless-to-near-colourless lab-grown service in October 2025.

A GIA laboratory-grown report issued under an older service may therefore look very different from a current GIA Quality Assessment. Do not conclude that an older report is fraudulent simply because it does not resemble today's version.

Instead, identify the issue date and verify it through the laboratory's official system.

This is one of the most important checks. The report should clearly identify the submitted stone as laboratory-grown where that is what was examined.

Do not assume a report bearing a familiar laboratory logo automatically means: natural diamond or: laboratory-grown diamond. Read the origin description.

An individual report may contain wording specifically identifying the stone as laboratory-grown and may provide additional growth information elsewhere on the document.

Origin and quality are separate questions. First establish what the diamond is. Then evaluate its characteristics.

Reports commonly identify the shape and cutting style of the stone. Examples include: Round Brilliant; Oval Brilliant; Cushion Brilliant; Cushion Modified Brilliant; Emerald Cut; Princess Cut; Pear Brilliant; Radiant Cut.

This tells you the basic faceted form of the diamond. Shape should not be confused with cut quality.

"Round Brilliant" describes the form and facet style. An applicable cut grade evaluates aspects of how effectively the stone has been proportioned and finished under that laboratory's grading methodology.

Measurements are normally given in millimetres. A round diamond may use a format such as: 6.45–6.49 × 3.95 mm. A fancy shape could appear as: 8.10 × 5.45 × 3.35 mm.

These figures typically represent relevant length, width and depth dimensions according to the shape and reporting system.

Measurements matter because carat is weight, not visible diameter or face-up size. Two diamonds can weigh exactly 1.00 ct but have noticeably different millimetre dimensions.

For the complete subject, see Diamond Carat Weight vs Size.

Carat measures diamond weight. One metric carat equals 0.20 grams, and one carat is divided into 100 points. So: 0.50 ct = half a carat; 1.00 ct = one carat; 1.50 ct = one and a half carats.

Do not assume carat automatically tells you how large the diamond will look. Depth, shape, proportions and face-up dimensions all influence visual size.

Also distinguish an individual stone's carat weight from total carat weight in multi-stone jewellery.

For that distinction, use What Does Total Carat Weight Mean?

On a detailed IGI report for a colourless-to-near-colourless lab-grown diamond, you may see an individual colour grade. For traditional D-to-Z diamond grading, letters towards D indicate less detectable body colour, with increasing visible tint further down the scale.

However, do not assume every laboratory-grown report currently displays an individual D-to-Z grade. GIA's current laboratory-grown Quality Assessment uses a different system.

Under its current criteria: a diamond qualifying for Premium must meet GIA's required D colour criterion along with its other Premium requirements. A stone can fall within Standard where its relevant criteria include colour from E through J, provided its other characteristics remain within the Standard/Premium framework.

That is why readers must identify the report type before interpreting the colour field.

On a detailed report such as an IGI Laboratory Grown Diamond Report, clarity may appear using familiar grading terminology such as: IF; VVS1; VVS2; VS1; VS2; SI1; and other applicable grades.

Clarity describes inclusions and blemishes visible under defined examination conditions. It should not be interpreted as a direct sparkle score. Nor does a higher clarity grade automatically mean the diamond is more beautiful in every practical situation.

GIA's current Premium/Standard assessment again works differently. Its current published criteria use clarity thresholds as part of the overall classification rather than presenting the service simply as the former lab-grown 4Cs report format.

For detailed clarity education, see Lab-Grown Diamond Clarity Grades Explained.

Some detailed diamond reports include a diagram showing clarity characteristics. Symbols can identify internal characteristics and external blemishes and indicate their approximate positions. This can help distinguish one diamond's internal feature pattern from another.

However, not every report type includes the same plotting diagram. Do not assume that the absence of a clarity plot means the report is invalid. The answer depends on the laboratory, service and document format.

Likewise, consumers should not attempt to diagnose diamond quality from a few plot symbols without understanding their context.

Cut is frequently misunderstood because it does not simply mean shape. For applicable diamonds and report systems, cut grading considers how successfully the finished diamond has been fashioned.

For standard round brilliants, factors can include proportions, brightness, fire, scintillation and aspects of design and craftsmanship. Fancy shapes may be treated differently depending on the laboratory and service.

So never assume: No cut-grade box = poorly cut diamond. The report type may simply not provide that particular grade for that shape. Use the actual report terminology.

For the full subject, read Lab-Grown Diamond Cut Explained.

Polish and symmetry describe aspects of the diamond's finish. Polish concerns the condition and quality of the facet surfaces. Symmetry concerns the precision of facet placement, alignment and related geometric relationships.

These are not identical to the overall cut grade. A report can therefore show separate entries for: Cut; Polish; Symmetry where the particular service provides all three.

Consumers should read each field independently rather than treating "Excellent Polish" as proof that every aspect of the diamond is Excellent.

Detailed reports may include a proportion diagram and information such as: table percentage; total depth percentage; crown angle or height; pavilion angle or depth; girdle thickness; and culet information.

These numbers describe the geometry of the polished diamond. They can be useful when comparing stones, but they should not be interpreted through simplistic rules such as: "one perfect table percentage guarantees the best diamond."

Proportions work together. The report provides data; the buyer still needs to understand the visual result.

The table is the large facet on the top of many faceted diamonds. A table percentage generally expresses its size relative to the width of the diamond according to the applicable measurement method.

It forms one part of the proportion system. A table figure alone cannot tell you whether a diamond will be beautiful. It needs to be considered alongside depth, crown, pavilion, shape and overall cut characteristics.

Depth percentage describes the relationship between the diamond's depth and relevant width measurement.

An unusually deep stone can hide more of its carat weight below the face-up view. An excessively shallow stone can create different optical problems. But there is no useful universal depth target that applies identically to every diamond shape.

For visible-size implications, use Diamond Carat Weight vs Size.

The girdle is the narrow outer perimeter separating the crown from the pavilion. Reports may describe its thickness using wording such as: Thin; Medium; Slightly Thick; Thick; or ranges combining several descriptions.

The girdle matters because it affects both proportions and physical vulnerability. Extremely thin areas may deserve attention, while unnecessarily thick girdles can retain weight that contributes less to face-up appearance.

The full diamond needs to be evaluated rather than judging the entire stone from one girdle word.

The culet is at or near the bottom point of a faceted diamond. Depending on design, the report may describe it with terminology such as: None; Pointed; Small; or another applicable description.

Again, this is one report field—not a complete quality conclusion by itself.

Fluorescence describes visible light emitted by the diamond when exposed to certain ultraviolet radiation. Reports may record an intensity such as: None; Faint; Medium; Strong; Very Strong depending on the laboratory system.

Do not automatically interpret fluorescence as a defect. Its practical visual significance varies.

In most ordinary purchasing situations, it should be considered alongside the complete diamond rather than used as an automatic rejection filter.

Some reported laboratory-grown diamonds have a microscopic inscription on the girdle. The inscription can contain a report number and may include wording identifying laboratory-grown origin depending on the laboratory and service.

For current qualifying GIA Laboratory-Grown Diamond Quality Assessments, GIA laser-inscribes the girdle with: Laboratory-Grown and the: GIA quality-assessment number.

IGI also offers report-linked laser inscription. The inscription can help connect the physical stone to its corresponding laboratory record. But not every laboratory-grown diamond worldwide necessarily carries one.

For the complete topic, use What Is a Diamond Laser Inscription?

The comments section can contain some of the most useful information on a laboratory-grown diamond report.

On IGI reports, comments may identify the growth process and provide information relating to post-growth treatment. For example, a report can state that a diamond was created using the: Chemical Vapour Deposition (CVD) growth process or: High Pressure High Temperature (HPHT) growth process.

It may also state that no post-growth treatment was indicated or that the diamond may include post-growth treatment.

These comments deserve attention because growth method and post-growth treatment are different things.

For the complete explanation, read CVD vs HPHT Lab-Grown Diamonds.

On applicable IGI documentation, wording such as: As Grown — No indication of post-growth treatment communicates that the laboratory did not detect evidence of post-growth treatment within its examination.

That does not mean the diamond was never cut or polished. It refers to treatment after crystal growth intended to alter certain characteristics.

Likewise, "as grown" should not automatically be interpreted as a superior quality grade. It describes manufacturing history.

A CVD-grown diamond may receive additional processing after growth. One recognised example is HPHT treatment intended to modify colour-related characteristics.

If the report includes a treatment comment, read it as information about the diamond's production history.

Do not confuse: CVD-grown with: HPHT-treated. A diamond can be both. That stone remains CVD-grown because CVD was the process that produced the crystal.

The following example is entirely illustrative. It does not reproduce or represent an actual Aurelia Royale diamond, an actual IGI report or any genuine laboratory record.

ILLUSTRATIVE EXAMPLE ONLY: Report number: EXAMPLE-ONLY-001 | Description: Laboratory-Grown Diamond | Shape and cutting style: Oval Brilliant | Measurements: 8.10 × 5.55 × 3.42 mm | Carat weight: 1.20 ct | Colour grade: F | Clarity grade: VS1 | Polish: Excellent | Symmetry: Excellent | Fluorescence: None | Growth-process comment: Illustrative CVD wording only | Inscription: Illustrative report-linking reference only.

These figures have been invented solely to demonstrate how report fields are read. They must not be presented as a genuine laboratory report or a specification for any Aurelia product.

"Laboratory-Grown Diamond" — This establishes the reported origin category.

"Oval Brilliant" — This identifies the shape and cutting style.

"8.10 × 5.55 × 3.42 mm" — These dimensions describe the physical size of our illustrative stone.

"1.20 ct" — This is its illustrative weight—not its physical width.

"F" — In this imaginary IGI-style example, the diamond has been assigned the illustrative colour grade F.

"VS1" — This is the illustrative clarity grade. It does not mean the diamond is flawless.

"Excellent Polish / Excellent Symmetry" — These describe separate finishing characteristics. They do not automatically mean every aspect of overall cut performance is perfect.

"None Fluorescence" — In this example, the report records no fluorescence under its applicable testing conditions.

Growth-method comment — If an actual IGI report identifies CVD or HPHT growth, that helps describe how the diamond was manufactured. The buyer should then check for any accompanying post-growth-treatment wording.

Again, none of the data above belongs to a real diamond.

An invented report number can easily be mistaken for a genuine laboratory record once an article is copied, screenshotted or quoted elsewhere. That creates unnecessary trust and compliance problems.

Aurelia Royale should therefore never publish wording such as: "Here is report LG123456789" unless that report genuinely exists and the brand has permission and a reason to use it.

For educational examples, use unmistakable identifiers such as: EXAMPLE-ONLY-001 and place a clear disclaimer immediately beside the sample. Do not rely on a small note at the bottom of the article.

This is the most important update for older versions of this article. Historically, GIA issued laboratory-grown diamond reports that contained detailed 4Cs-style information. That changed for its principal D-to-Z laboratory-grown service on 1 October 2025.

GIA's current Laboratory-Grown Diamond Quality Assessment provides an overall quality classification of: Premium or: Standard for eligible loose colourless-to-near-colourless laboratory-grown diamonds weighing at least 0.15 ct.

It therefore should not be described as though it were simply the same document as an IGI detailed lab-grown 4Cs report.

Under GIA's current published criteria, a laboratory-grown diamond has to satisfy all applicable Premium requirements to receive the overall Premium assessment. Those criteria include stringent thresholds relating to: colour; clarity; polish; symmetry; and cut for applicable round brilliant diamonds.

The word Premium is therefore an overall GIA laboratory-grown assessment category. It should not be rewritten on a product page as though GIA had issued a conventional natural-diamond D/IF-style grading report under the current service.

GIA's Standard category covers eligible diamonds meeting combinations of its published Premium and Standard criteria. If a stone falls outside the minimum criteria required for Standard, GIA states that it does not receive a Laboratory-Grown Diamond Quality Assessment under this service.

This again illustrates why: "Read the colour and clarity grade on every GIA lab certificate" is now outdated advice. The document type comes first.

Older genuine GIA Laboratory-Grown Diamond Reports can still exist. Before October 2025, GIA used a different reporting system for laboratory-grown diamonds.

A buyer may therefore encounter a genuine historical report containing detailed 4Cs information that does not resemble the current Premium/Standard assessment. Do not rewrite history by claiming those reports were never issued.

Instead: check the report date; verify the report number through GIA; and interpret the document according to the service in use when it was issued.

This table is deliberately general. Always use the current issuing laboratory's own documentation as the final authority for a particular report.

Do not verify an IGI report through a random third-party website. Use IGI's official report-verification system. Enter the report number exactly as shown.

Then compare the retrieved laboratory record with the document and diamond information provided by the seller. Important fields to compare include: report number; description; shape; measurements; carat weight; colour and clarity information where applicable; and relevant comments.

Where an associated laser inscription is present and can be examined safely, it may provide another connection between the physical diamond and laboratory record.

For the full IGI-specific process, see How to Verify an IGI Diamond Report Online.

Use GIA Report Check. GIA's official Report Check service allows users to enter a report number and compare the report information against data stored in GIA's database.

This is much stronger verification than simply accepting a photograph or PDF sent by a retailer.

If you are looking at an older GIA lab-grown report, the verification result can also help establish that the apparently different historical format corresponds to an archived GIA record.

Online verification proves that the report number and archived laboratory record correspond. You still need to establish that the physical diamond being sold is the stone associated with that document.

Where a matching girdle inscription is present, it can help establish that connection. Measurements and other identifying information can provide additional consistency checks.

Therefore: Report verification = verify the laboratory record. Physical matching = establish that the actual stone corresponds to that record. They are related but not identical tasks.

No. A report number etched onto a girdle should be checked against the issuing laboratory's official record. Do not assume that seeing numbers under magnification proves every accompanying claim.

Verify the record and compare the available characteristics. Likewise, the absence of an inscription does not automatically mean a diamond is fake or natural. Inscription practices depend on laboratory, service, stone and circumstances.

Do not immediately conclude fraud, but do not ignore the problem either. First, check for typing errors. Confirm whether letters, prefixes, spaces or digits were entered correctly.

Then check that you are using the correct laboratory's official verification system. Older reports and different services can have different online-access arrangements.

If the record still cannot be verified, ask the seller and issuing laboratory for clarification before relying on the document.

No. A laboratory report provides gemmological information. It does not automatically provide a cash resale value, retail selling price or insurance replacement value.

GIA explicitly states that it does not appraise submitted gemstones and does not put an appraisal value on its reports. IGI similarly states in its report limitations that its report should not be relied upon as an appraisal, warranty or guarantee.

For financial value, see Do Lab-Grown Diamonds Have Resale Value?

No. A report helps you understand the stone. Price is a separate commercial question.

Two diamonds can carry similar quality information while having different: dimensions; visual characteristics; growth histories; retail margins; settings; and final jewellery prices.

A laboratory report should make comparison easier. It should not stop comparison.

No. A report describes specified characteristics under defined laboratory procedures. Beauty and preference remain visual and personal.

For example, two oval diamonds can share the same carat weight, colour and clarity while having different length-to-width ratios. One may be long and slender. Another may be shorter and broader. A buyer may strongly prefer one shape outline.

The report provides data for that decision rather than making the decision for you.

No. An individual diamond report does not assess the complete ring, earring, bracelet or necklace unless the entire jewellery article was actually submitted under an appropriate jewellery-reporting service.

A centre-stone report does not automatically tell you about: prong security; clasp quality; metal finishing; chain durability; sizing; comfort; or overall workmanship.

For that question, see What Makes Lab-Grown Diamond Jewellery High Quality?

No. A precious-metal hallmark and a diamond laboratory report perform different functions. In the UK, hallmarking concerns qualifying precious-metal fineness. It does not provide the diamond's carat, colour, clarity, cut or laboratory-grown origin grading.

A ring can therefore carry a legitimate precious-metal hallmark and separately have a laboratory report for its centre diamond. Neither replaces the other.

You do not need to become a gemmologist to use a diamond report effectively. For most buyers, begin with: Origin: Is it explicitly laboratory-grown? | Report type: What document are you actually reading? | Report number: Can it be verified? | Carat: What does the stone weigh? | Measurements: How large is it physically? | Colour and clarity: What does the relevant laboratory report? | Cut/proportions: What information is available for that shape and service? | Comments: Is growth method or treatment information provided? | Inscription: Is there a report-linked girdle inscription?

Those fields give you a strong first reading.

Almost all of them. Carat without measurements can mislead you about visible size. Clarity without understanding the actual characteristics can encourage unnecessary overpayment. Colour without considering setting and visual preference can be overemphasised. Table percentage without the other proportions cannot describe cut performance. Fluorescence by itself should not automatically disqualify a diamond.

A report works best as a connected set of information, not a collection of independent scores to maximise.

Carat is easy to understand, which makes it easy to overvalue. Two 1 ct diamonds can face up at different physical dimensions. A deep diamond can carry more of its weight below the visible surface. Always read measurements alongside carat.

A higher clarity grade indicates fewer or less significant clarity characteristics under the grading system. It does not mean every buyer needs that grade.

A visually clean lower-clarity diamond may suit a particular purchase perfectly. The report informs the decision rather than telling you to buy the highest possible grade.

On laboratory-grown diamond reports, comments can contain particularly important origin, growth-method or treatment information. Do not stop reading after the 4Cs.

The bottom or comments portion of the report may explain whether the diamond is CVD- or HPHT-grown and provide treatment-related wording where applicable.

This is now one of the most serious errors in outdated lab-grown diamond content. IGI continues to provide detailed 4Cs-style laboratory-grown diamond reports. GIA's current qualifying colourless-to-near-colourless lab-grown service uses Premium and Standard classifications. Other report types can differ again.

Always identify the issuing laboratory and service before interpreting the fields.

A PDF can be copied, edited or detached from the physical stone it originally described. Where official online verification is available, use it.

Then compare the retrieved record with both the document and the stone information. The existence of a professional-looking PDF is not the final verification step.

Do not begin by searching for the highest colour or clarity grade. Begin by understanding what document you have.

Identify the issuing laboratory. Identify the report type. Confirm that the diamond is described as laboratory-grown. Check the report number and issue date. Then examine the stone's measurements, carat weight and the quality information actually provided by that laboratory. Read the additional comments. Look for growth-method and treatment information where applicable. Check any relevant laser inscription. Finally, verify the report through the issuing laboratory's official database.

Most importantly, do not assume every lab-grown diamond report works the same way.

An IGI Laboratory Grown Diamond Report can provide detailed individual 4Cs information. A current GIA Laboratory-Grown Diamond Quality Assessment uses a different Premium/Standard system. A finished-jewellery report can contain still different information because the stones are being examined while mounted.

Understanding those distinctions is far more useful than simply asking whether a diamond is "certified".

For whether an individual report is necessary, read Do Lab-Grown Diamonds Need Certification?

For loose-stone versus finished-jewellery documentation, use Diamond Certification vs Jewellery Certification.

For IGI specifically, continue with What Is an IGI Lab-Grown Diamond Certificate?

For report verification, read How to Verify an IGI Diamond Report Online.

For laser inscriptions, use What Is a Diamond Laser Inscription?

And when considering an Aurelia Royale piece, check the documentation stated for the specific design or diamond rather than assuming one laboratory or report format applies to the entire catalogue.

Where a design is not currently available for direct purchase, Join the Waitlist or submit an enquiry to register your interest.