Quick answer: An IGI lab-grown diamond report identifies the examined diamond and records its origin, shape, measurements, carat weight, color, clarity, cut information, finish, fluorescence, inscription, and relevant comments. Some reports also include proportion or clarity diagrams. It does not guarantee beauty, price, ownership, durability, ethical sourcing, or that the seller matched the report to the correct stone.
An IGI report can look reassuringly precise.
It contains measurements to hundredths of a millimeter, standardized diamond grades, a report number, technical comments, diagrams, barcodes, and sometimes a photograph of the laser inscription.
Yet buyers frequently read only four lines:
- Carat weight
- Color
- Clarity
- Cut
That leaves some of the most important information unread.
The description establishes whether the diamond is natural or laboratory-grown. Measurements help determine whether the report belongs to the stone. The comments can reveal CVD or HPHT growth and post-growth treatment. The proportion diagram can explain where the diamond carries its weight. The limitations clarify that the report is not an appraisal or warranty.
This guide walks through an IGI report in the order a buyer should read it.
Before Reading the Fields, Identify the Report Type
IGI issues several kinds of documents. Their fields and conclusions are not identical.
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A seller should state which document is supplied and whether it describes the loose center diamond or the complete jewelry item.
The word “certified” alone does not answer that question.
For a clear overview of grading documents, read our diamond certification guide before comparing any IGI-reported jewelry.
The IGI Report Anatomy Map
A current loose laboratory-grown diamond report may contain the following groups of information:
- Report title and issue date
- Unique IGI report number
- Diamond description and origin
- Shape and cutting style
- Measurements
- Carat weight
- Color grade
- Clarity grade
- Cut grade, when applicable
- Polish and symmetry
- Fluorescence
- Laser inscription
- Comments
- Proportion diagram
- Clarity-characteristic diagram, when included
- QR code, barcode, and security information
- Terms and limitations
Not every report contains every field.
The diamond’s shape, color category, report service, size, and mounted or loose condition can change what IGI is able or contracted to report.
1. Report Title
The title tells you which IGI service produced the document.
Examples may include:
- Laboratory Grown Diamond Report
- Laboratory Grown Diamond Jewelry Report
- Fancy Colored Diamond Report
- Diamond Identification Report
Do not assume that every IGI document is a full loose-diamond grading report.
A jewelry report may identify mounted stones and metal but have limitations caused by the setting. An identification document may confirm material and origin without supplying every 4C or proportion field.
Buyer action
Compare the report title with the seller’s claim. When a product page advertises a “full IGI report,” ask which exact report type will be supplied.
2. Report Date
The date records when IGI issued the report.
It does not tell you:
- When the diamond was grown
- When it was cut
- When it was set into jewelry
- When the retailer acquired it
- Whether it has been worn or damaged since examination
A report accurately matched to a diamond can remain useful over time, but the condition of the stone may change after grading.
A chipped girdle, abrasion, repolishing, recutting, or new inscription may make the historical report incomplete for the diamond’s current condition.
Buyer action
Inspect the current diamond even when the report is authentic, particularly when purchasing preowned or reset jewelry.
3. IGI Report Number
The report number is the unique identifier connecting the printed or electronic document to IGI’s online record.
Laboratory-grown diamond report numbers commonly include an “LG” prefix.
The number may appear:
- In the main identification section
- Beside a barcode
- In the tear-off summary portion
- Within the QR-linked digital record
- In the diamond’s laser-inscription field
A valid number confirms that IGI has an online record. It does not by itself prove that the seller’s physical diamond is the one described.
Buyer action
Use IGI’s official verification service and then match the report with the inscription, shape, measurements, carat weight, and visible characteristics.
For the complete verification process, read how to verify an IGI report number before buying.
4. Description
This field identifies the type of material IGI examined.
For the diamonds covered by this guide, it should state:
LABORATORY GROWN DIAMOND
This is one of the most important fields on the report.
It distinguishes a laboratory-grown diamond from:
- A naturally mined diamond
- Moissanite
- Cubic zirconia
- Glass
- Another diamond imitation
FTC guidance requires sellers to place a clear origin qualifier such as “laboratory-grown” or “laboratory-created” immediately before the word “diamond.”
To understand the stone’s origin, learn what a lab-grown diamond is and how it differs from a naturally mined diamond.
Buyer action
Make sure the product page, invoice, and report all describe the center stone consistently as a laboratory-grown diamond.
5. Shape and Cutting Style
This field combines two related but different facts.
- Shape describes the face-up outline.
- Cutting style describes the facet arrangement.
Examples include:
- Round Brilliant
- Oval Modified Brilliant
- Heart Modified Brilliant
- Emerald Cut
- Cushion Modified Brilliant
“Modified brilliant” is not a negative grade. It identifies a facet style derived from brilliant-cutting principles.
The field also does not indicate whether the outline is visually attractive or whether a fancy shape has an undesirable bow tie, uneven shoulders, poor corner balance, or weak light return.
Buyer action
Confirm that the report’s shape matches the diamond shown and evaluate the exact outline through realistic video.
6. Measurements
Measurements are among the most useful report-matching and value-comparison fields.
A round diamond is generally recorded as:
Minimum diameter – maximum diameter × depth
A fancy shape is generally recorded as:
Length × width × depth
Measurements explain how the diamond distributes its carat weight.
Two diamonds with the same carat weight may have different:
- Face-up diameter
- Length and width
- Total depth
- Visible finger coverage
- Setting requirements
A deeper diamond can hide more weight beneath the girdle. A shallower stone may appear larger from above but can display weak light return when its proportions are unsuitable.
Buyer action
Compare millimeters—not only carats—and make sure a custom setting is built for the exact dimensions on the report.
7. Carat Weight
Carat measures weight, not visible size.
One carat equals 0.20 grams.
IGI states that diamonds are weighed to greater precision during grading and reported to two decimal places.
A report showing 2.00 carats does not tell you whether the diamond will look larger than another 2.00-carat stone. Shape, dimensions, total depth, and cutting proportions control face-up spread.
Buyer action
Use carat weight together with measurements and proportion information. Do not pay for a threshold such as 2.00 carats without checking how much of that weight is visible.
8. Color Grade
Colorless-to-light-yellow or brown diamonds commonly receive a grade on the D-to-Z scale.
- D is at the colorless end.
- Grades progress through near-colorless and increasingly tinted ranges.
- The grade is assessed under standardized conditions rather than from a product photograph.
A higher color grade is not automatically the best value for every setting.
The diamond’s face-up appearance can also be influenced by:
- Shape
- Cutting style
- Size
- Fluorescence
- Metal color
- Nearby gemstones
Fancy-colored diamonds
A pink, blue, green, yellow, or another fancy-colored diamond uses a color description rather than a simple D-to-Z grade.
For example, a report may state “Fancy Pink.”
Do not compare that description directly with a D, E, F, or another colorless-diamond grade.
Buyer action
Review the diamond face-up in several lighting conditions. The color grade is essential, but it does not replace your visual preference.
9. Clarity Grade
IGI evaluates clarity at 10× magnification according to the visibility, size, number, location, and nature of internal and surface characteristics.
The scale includes categories such as:
- Internally Flawless
- Very Very Slightly Included
- Very Slightly Included
- Slightly Included
- Included
The clarity grade does not tell you automatically whether the diamond is eye-clean.
Two diamonds with the same grade can contain different features in different locations.
A small inclusion near the girdle may be difficult to see. A dark characteristic beneath the table may be more noticeable despite receiving the same grade.
Review the lab-grown diamond clarity guide to understand inclusion location, eye-clean appearance and clarity grades.
Buyer action
Review the clarity plot when supplied, request magnified video, and ask whether any inclusion is visible without magnification or positioned near a vulnerable point.
10. Cut Grade
Cut grade is one of the most frequently misunderstood fields.
It evaluates how successfully the diamond’s proportions and craftsmanship work together under the grading system applied to that shape.
A current round brilliant report may include a grade such as Ideal.
A fancy-shaped report may:
- Include an optional IGI fancy-shape cut grade
- Contain only polish and symmetry grades
- Omit an overall cut grade
The absence of a cut grade does not mean the diamond has no cut quality. It means you must rely more heavily on measurements, proportions, finish, shape-specific appearance, and video.
Buyer action
Do not compare a round cut grade directly with a fancy-shape report that uses a different assessment scope.
11. Polish
Polish assesses the quality of the finished facet surfaces.
Polish characteristics can include:
- Polishing lines
- Abrasions
- Burn marks
- Surface grain lines
- Other finishing irregularities
A high polish grade supports clean light transmission and professional finishing.
It does not prove that the diamond has excellent proportions or visual performance.
Buyer action
Use polish as one craftsmanship field, not as a substitute for the overall cut evaluation.
12. Symmetry
Symmetry assesses the precision of the diamond’s outline and the placement, alignment, and relationship of its facets.
Symmetry issues may include:
- An off-center table
- Misaligned facets
- Uneven girdle thickness
- An off-center culet
- Outline irregularities
An Excellent symmetry grade is valuable, but it does not guarantee ideal light performance or an attractive fancy-shape outline.
Buyer action
Inspect ovals, pears, hearts, cushions, marquises, and geometric diamonds visually even when the symmetry grade is high.
13. Fluorescence
Fluorescence describes the diamond’s reaction to ultraviolet light.
The report may record a strength such as:
- None
- Faint
- Medium
- Strong
- Very Strong
Fluorescence is not the same thing as the diamond’s bodycolor, and it is not automatically a defect.
Its visible effect varies according to the individual diamond, fluorescence color, strength, lighting environment, and underlying color grade.
Buyer action
When fluorescence is strong, ask for video in daylight and ordinary indoor light rather than rejecting or accepting the diamond from the report field alone.
14. Inscription Field
The inscription field records the alphanumeric information observed or applied on the diamond’s girdle.
IGI states that every laboratory-grown diamond it grades receives an inscription identifying laboratory-grown origin. A report number may also be laser inscribed to connect the stone with its document.
The inscription is microscopic and may require a loupe or microscope to read.
It can also be:
- Partly hidden beneath a prong
- Difficult to locate on a mounted stone
- Reduced or removed through repolishing
- Fraudulently copied onto another diamond
Buyer action
Use the inscription together with online verification and measurements. An inscription alone is not a complete authenticity check.
15. Comments
The comments section can contain the most consequential information on a laboratory-grown diamond report.
It may state:
- CVD growth process
- HPHT growth process
- No indication of post-growth treatment
- Indications of post-growth treatment
- A qualified treatment statement
- Type II classification
- Additional inscriptions
- Special cutting or optical comments
Do not stop reading after the 4Cs.
Growth process
CVD and HPHT identify how the diamond crystal was created. They are not quality grades.
Post-growth treatment
This indicates whether IGI detected processing applied after the diamond was grown.
Read the HPHT post-growth treatment guide for the difference between growth and treatment.
Type II
Type II describes a diamond-classification category associated with its measurable impurity characteristics.
It is not a clarity, cut, color, rarity, or treatment grade.
Buyer action
Preserve the exact comments on the product page and invoice rather than replacing them with simplified claims such as “untreated” or “HPHT diamond.”
16. Proportion Diagram
The proportion diagram shows the diamond’s geometry in a standardized side view.
Depending on the shape and report, it may display:
- Table percentage
- Total depth percentage
- Crown angle
- Crown height percentage
- Pavilion angle
- Pavilion depth percentage
- Girdle thickness and finish
- Culet size or condition
The diagram is not a photograph of the actual diamond and is not a direct light-performance image.
It summarizes measured proportions using a representative outline.
Why buyers should care
The diagram can help explain:
- Why a diamond looks large or small for its carat weight
- Whether it carries excessive depth
- How thick the girdle is
- Whether the culet is pointed or visible
- How it may fit into a setting
One percentage should not be judged in isolation. Diamonds work through combinations of angles, heights, facet relationships, and craftsmanship.
17. Clarity Plot
Some full reports include a diagram mapping relevant internal and external clarity characteristics.
The plot can help:
- Identify the diamond
- Show where important inclusions are located
- Explain part of the clarity grade
- Flag characteristics near the girdle or points
The plot is not necessarily a drawing of every microscopic feature.
It is also not a precise prediction of what the unaided eye will see.
Some report formats or smaller diamonds may not include a full clarity plot.
Buyer action
Use the plot with magnified imagery and realistic face-up video. Ask the seller to locate any feature that may affect appearance or setting safety.
18. QR Code, Barcode and Security Features
Current IGI reports can include a QR code linking to the corresponding online document.
Printed reports may also contain security features such as:
- Special security paper
- Microprinting
- Holographic elements
- Watermark or background patterns
- Barcodes
A visually convincing paper document can still be altered or paired with the wrong diamond.
Buyer action
Scan the QR code or enter the report number through IGI’s official website. Compare the online document with the paper copy field by field.
19. Report Limitations
The limitations are not decorative fine print.
IGI states that its report provides an opinion and is not:
- A guarantee
- An appraisal
- A warranty
- Proof of ownership
- A promise of resale value
IGI also notes that laboratory opinions may vary according to when, how, and by whom an item was examined, and that treatment and synthesis technologies continue to evolve.
The report does not generally establish:
- The selling price
- Whether the price is fair
- Ethical sourcing
- Carbon emissions
- The quality of the ring setting
- Prong security
- Return eligibility
- Insurance replacement value
- Whether the wearer will find the diamond beautiful
Loose Diamond Report vs Jewelry Report
A report for a finished ring should not be interpreted as though IGI examined the center diamond loose.
IGI states that its laboratory-grown diamond jewelry reports can describe:
- The complete article
- Mounted gemstone identities
- Precious-metal content
- Purity stamps, when present
- Center-stone shape and cutting style
- Measurements and 4C information as the mounting permits
A mounting can obstruct:
- Exact weight determination
- Complete girdle inspection
- Some inclusions
- Full proportion measurement
- Laser-inscription visibility
For a premium engagement ring, ask whether the center stone has its own loose-diamond report in addition to any finished-jewelry documentation.
Browse lab-grown diamond engagement rings and compare certified center stones, setting styles, shapes and carat options.
What an IGI Report Proves—and What It Does Not
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The Five-Minute Buyer Review
- Verify the report number through IGI.
- Confirm that the description states laboratory-grown diamond.
- Match the shape, measurements, and carat weight.
- Read the color, clarity, and applicable cut fields.
- Inspect polish, symmetry, and fluorescence.
- Read every word in the comments section.
- Match the laser inscription where accessible.
- Review the proportion and clarity diagrams when included.
- Compare the report with realistic photographs and video.
- Save the report, invoice, and product disclosure.
Before ordering online, use our lab-grown diamond buying guide to compare certification, quality, value and seller disclosures.
What a Product Page Should State
A transparent IGI-certified jewelry listing should identify:
- Which diamond has the IGI report
- Whether the report describes a loose stone or finished jewelry
- The report number
- Laboratory-grown origin
- Shape and cutting style
- Measurements
- Carat weight
- Color and clarity
- Cut information where applicable
- Growth and treatment comments
- Whether the report is available before purchase
A clear disclosure may read:
The center stone is an IGI-graded laboratory-grown diamond. Report number LG[NUMBER] identifies its shape, measurements, carat weight, color, clarity, cut information, and relevant growth or treatment comments. Accent-diamond specifications are listed separately and are not represented by the center-stone report.
This prevents a center-stone report from being misunderstood as certification of every diamond, the metalwork, or the complete ring.
Explore IGI-certified diamond jewelry to compare documented center stones, shapes and settings before choosing your design.
IGI Report Red Flags
Pause the purchase when:
- The seller will not provide the report number before payment
- The online IGI record does not load
- The report description conflicts with the product page
- The measurements do not match the stone being offered
- The comments section is cropped or hidden
- A jewelry report is presented as a loose-diamond report
- The laser inscription belongs to another report
- “Type II” is marketed as an overall quality grade
- An absent fancy-shape cut grade is replaced with an unsupported seller grade
- The report is described as an appraisal or resale guarantee
- The center-stone report is presented as covering every accent stone
- The invoice omits laboratory-grown origin
Use the Report as a Map, Not the Destination
An IGI report gives a buyer a standardized description of the diamond that was examined.
It helps establish origin, dimensions, grading characteristics, growth information, treatment comments, and identifiers.
It cannot tell you whether the ring will sit comfortably, whether the prongs are secure, whether the diamond looks lively in ordinary light, or whether the price makes sense compared with another option.
Read every field.
Match the document to the stone.
Then evaluate the finished jewelry as a complete object.
Explore Rosec Jewels’ IGI-certified lab-grown diamond jewelry to compare documented engagement rings, bridal sets, earrings, and fine-jewelry designs.
For general certificate information, review the Rosec Jewels diamond certification guide.
For help interpreting the exact report supplied with a product, contact Rosec Jewels with the product link and complete report number before ordering.
Frequently Asked Questions
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What is an IGI diamond report?
It is an independent gemological opinion describing the diamond examined by IGI. Depending on the service, it can identify origin, measurements, 4Cs, finish, fluorescence, proportions, inscriptions, growth process, and treatment information.
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Is an IGI report the same as a certificate?
Shoppers often call it an IGI certificate, but the document itself is a grading report and expert opinion. IGI states that it is not a guarantee, appraisal, or warranty.
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What is the most important field on an IGI report?
No single field is sufficient. Begin with the description and report number, then review the measurements, 4Cs, inscription, and comments together.
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Where does an IGI report say that the diamond is lab-grown?
The description should state “Laboratory Grown Diamond.” The comments may also identify CVD or HPHT growth, while the girdle inscription identifies laboratory-grown origin.
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Does every IGI report include a cut grade?
No. Round brilliant reports commonly include an overall cut grade. Fancy-shape cut grading is optional, and some fancy-colored or other report formats may omit the overall cut field.
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Why does my IGI report not have a clarity plot?
Clarity diagrams depend on the report type, diamond, size, and service. The absence of a plot does not automatically invalidate the report.
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What do diamond measurements mean?
They describe the diamond’s physical dimensions in millimeters. Rounds are generally shown by minimum diameter, maximum diameter, and depth; fancy shapes are generally shown by length, width, and depth.
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Does carat weight show how large the diamond looks?
No. Carat measures weight. Measurements, shape, depth, and proportions determine the visible face-up size.
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Does an IGI clarity grade mean the diamond is eye-clean?
No. Clarity is graded at 10× magnification. Visibility to the unaided eye depends on inclusion type, size, color, location, diamond size, and viewing conditions.
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What does Type II mean on an IGI report?
It is a scientific diamond-type classification related to impurity characteristics. It is not an overall quality, clarity, cut, color, or treatment grade.
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Where is post-growth treatment disclosed?
It is generally stated in the comments section when the applicable information is included. Read the exact wording rather than assuming that CVD or HPHT identifies treatment.
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Does fluorescence lower a diamond’s quality?
Not automatically. The report records the fluorescence strength, but its visible impact must be judged on the individual diamond in relevant lighting.
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How do I know whether the report belongs to the diamond?
Verify the report online and compare the laser inscription, shape, measurements, carat weight, and visible characteristics. Use more than the report number alone.
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Can a fake diamond carry a copied IGI inscription?
An inscription can potentially be copied or altered. That is why buyers should verify the online report and match several physical characteristics rather than relying only on the girdle number.
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Does an IGI report show the diamond’s value?
No. A grading report is not a price estimate or appraisal. Value also depends on market conditions, visual quality, rarity, setting, brand, and sales terms.
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Does an IGI report certify the complete engagement ring?
A loose-diamond report describes only the diamond examined. A separate jewelry report may describe the finished article as mounting permits. Check which document is supplied.
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Does an IGI report prove ethical sourcing?
No. It identifies and grades the diamond within its report scope. Ethical sourcing, labor conditions, energy use, carbon emissions, and chain of custody require different evidence.
Choose Your IGI-Certified Lab-Grown Diamond Ring
Discover IGI-certified lab-grown diamond engagement rings with verified quality, beautiful designs and clearly documented center-stone details.
Authoritative Sources
- International Gemological Institute: How to Read a Laboratory-Grown Diamond Report
- IGI: How to Read a Diamond Grading Report
- IGI: Laboratory-Grown Diamond Report and Report Scope
- IGI: Diamond Grading Process, Measurement and Reporting
- IGI: Verify Your Report and Report Limitations
- IGI: Diamond Laser-Inscription Service
- IGI Report Example: Round As-Grown HPHT Laboratory Diamond
- IGI Report Example: Fancy-Pink CVD Laboratory Diamond With Post-Growth Treatment
- Federal Trade Commission: Laboratory-Grown Diamond Disclosure Guidance