How to Read a GIA Diamond Report

To read a GIA diamond report, first verify its report number through GIA Report Check. Confirm the report type, date, shape, measurements and carat weight. Then review colour, clarity and cut grade where applicable, followed by polish, symmetry, fluorescence, proportions, clarity characteristics, comments and inscription information. Finally, compare the report with the diamond, supplier listing, images and video.

A GIA report documents the characteristics GIA observed. It is not a valuation, proof of ownership or guarantee that the physical diamond being offered matches the document.

Verify a report using GIA Report Check.

Is It a GIA Certificate or a GIA Report?

Many buyers use the phrase “GIA certificate,” but GIA calls its document a report.

This distinction matters because a grading report records an expert assessment of a diamond’s characteristics. It does not certify a selling price, investment return or future value.

GIA’s own limitations state that a GIA report is not a guarantee, valuation or appraisal. Read the official limitations for GIA reports.

For a broader introduction to grading documents, read the Diamond Grading Report Guide.

Start by Identifying the Report Type

GIA offers different report services, and the information or presentation can vary by report type.

Current natural-diamond services listed by GIA include:

• Diamond Grading Report
• Diamond Origin Report
• Diamond Dossier
• Diamond eReport
• Diamond Focus Report

The standard Diamond Grading Report includes a full 4Cs assessment and a plotted clarity diagram. Other report types can differ in eligible carat range, digital presentation, inscription requirements, origin information, face-up imagery or clarity-documentation format.

Always read the report title before interpreting its fields. Do not assume every GIA document contains the same sections.

See GIA’s current natural-diamond reports and services.

1. Report Date

The report date shows when GIA examined the diamond.

It does not function as a simple expiry date. However, the report describes the diamond at the time of examination.

A later event could affect whether the diamond still matches the report, including:

• Damage
• Chipping
• Recutting
• Repolishing
• Replacement
• Addition or removal of an inscription

For an older report, confirm the diamond’s current condition and identity. Where condition or identity is uncertain, updated professional assessment may be appropriate.

2. GIA Report Number

The report number is the unique reference associated with the GIA report record.

Use the number to locate the report through GIA Report Check.

When checking the number:

1. Enter it directly on the official GIA website.
2. Confirm that a report record appears.
3. Compare the report type and date.
4. Compare shape, measurements and carat weight.
5. Compare colour, clarity and other grading information.
6. Review inscriptions and comments.
7. Match the information with the diamond being offered.

Finding a valid number proves that a corresponding GIA record exists. It does not prove that the seller possesses that diamond or that the stone in front of you is the one described.

3. Shape and Cutting Style

This field identifies the diamond’s outline and facet arrangement.

Examples include:

• Round Brilliant
• Oval Brilliant
• Pear Brilliant
• Cushion Modified Brilliant
• Emerald Cut
• Radiant Cut
• Princess Cut
• Marquise Brilliant

Shape is not the same as cut grade.

“Round Brilliant” describes shape and cutting style. “Excellent” can describe the overall cut grade of an eligible standard D–Z Round Brilliant.

For fancy shapes, use measurements, proportions and visual assessment rather than assuming the report provides the same overall cut grade used for standard Round Brilliants.

4. Measurements

Measurements record the diamond’s dimensions in millimetres.

A Round Brilliant is generally shown as:

minimum diameter – maximum diameter × depth

A fancy-shaped diamond is generally shown as:

length × width × depth

Examples:

Round: 6.44–6.48 × 3.97 mm

Oval: 9.15 × 6.35 × 3.92 mm

Measurements help you assess:

• Face-up size
• Outline
• Length-to-width ratio
• Weight distribution
• Whether the offered diamond matches the report

Two diamonds can have the same carat weight but different visible dimensions.

GIA describes these measurement formats in its guide to reading a diamond grading report.

5. Carat Weight

Carat measures weight. One carat equals 0.20 grams.

Example: 1.01 carat

Carat weight does not tell you:

• How large the diamond appears face-up
• Whether its proportions are attractive
• How well it handles light
• Whether its price is appropriate

Compare the carat weight with the measurements and proportions.

For complete carat guidance, see the Diamond Carat Weight Guide.

6. Colour Grade

For natural diamonds in the normal D–Z range, the colour grade assesses the relative absence of colour.

The scale begins at D and continues through Z.

A report might show:

Colour grade: G

Do not interpret the letter in isolation. The visible effect of colour can also depend on:

• Diamond shape
• Size
• Setting metal
• Lighting
• Viewing direction
• Personal preference

This page should not repeat the complete colour scale. Read Diamond Colour Grades D–Z for detailed buying guidance.

7. Clarity Grade

Clarity grades reflect the relative absence of inclusions and blemishes under GIA’s grading conditions.

The scale includes:

• FL
• IF
• VVS1 and VVS2
• VS1 and VS2
• SI1 and SI2
• I1, I2 and I3

A report might show:

Clarity grade: VS2

The grade alone does not reveal whether an inclusion is easily visible face-up. Visibility and possible durability relevance depend on factors such as:

• Inclusion type
• Size
• Number
• Position
• Relief
• Orientation
• Diamond shape
• Viewing conditions

Review the clarity characteristics, plot where provided, comments and the actual diamond.

For complete clarity guidance, read Diamond Clarity Grades Explained.

8. Cut Grade

For eligible standard Round Brilliant diamonds in the D–Z colour range, a GIA report can provide an overall cut grade.

GIA’s cut-grade scale runs from:

• Excellent
• Very Good
• Good
• Fair
• Poor

GIA explains that this cut grade considers face-up appearance, design and craftsmanship. It is not determined by one measurement alone.

A report might show:

Cut grade: Excellent

Excellent is the highest category on this grading scale, but it does not mean every Excellent-cut diamond looks identical. Diamonds in the same category can have different proportions, patterns and visual character.

Do not expect the same conventional GIA overall cut grade on every fancy-shaped diamond. If the report does not show an overall cut grade, do not invent one from polish and symmetry.

See GIA’s natural-diamond report details and Dalila’s Diamond Cut Quality Explained.

9. Polish

Polish describes the quality and condition of the diamond’s facet surfaces.

The report may show:

• Excellent
• Very Good
• Good
• Fair
• Poor

Polish is separate from overall cut grade.

An Oval with Excellent polish has well-finished facet surfaces according to the report. That does not mean GIA has assigned the Oval an Excellent overall cut grade.

10. Symmetry

Symmetry assesses the exactness of the diamond’s outline and the placement, shape and alignment of its facets.

The report may show:

• Excellent
• Very Good
• Good
• Fair
• Poor

Symmetry is also separate from overall cut grade.

A fancy-shaped diamond can have Excellent symmetry while still displaying an outline, bow-tie pattern or facet appearance that a buyer does not prefer.

11. Fluorescence

The fluorescence field records the strength and colour of visible light produced when the diamond is exposed to long-wave ultraviolet radiation under the laboratory’s conditions.

Descriptions may include:

• None
• Faint
• Medium
• Strong
• Very Strong

The report may also identify a fluorescence colour.

Fluorescence is not automatically good or bad. Its visual and commercial relevance depends on the individual diamond, strength, body colour, appearance and buyer preference.

Inspect the diamond under relevant lighting instead of rejecting or accepting it solely from this field.

12. Inscription Information

The inscriptions section records inscriptions observed on the girdle when included in the report.

It may contain:

• A GIA report number
• A brand name
• A logo
• Personal text
• Another identifying inscription

Do not assume every GIA-graded diamond has a report-number inscription. Check the individual report.

Where an inscription is recorded:

1. Inspect it with suitable magnification.
2. Compare the characters with the report.
3. Check the diamond’s measurements and weight.
4. Compare relevant clarity characteristics.
5. Investigate any inconsistency.

An inscription is an important matching tool, but it should be considered with the other identifying information.

13. Proportion Diagram

Depending on the report type and shape, the report may display a proportion diagram with information such as:

• Table percentage
• Total depth percentage
• Crown angle or height
• Pavilion angle or depth
• Star length
• Lower-half length
• Girdle description
• Culet size

These values explain part of the diamond’s geometry.

Table percentage

The table is the large facet at the top of the diamond. Table percentage compares its width with the diamond’s relevant width or average diameter.

Depth percentage

Total depth percentage compares the diamond’s depth with its width or average diameter, according to the shape and reporting convention.

Crown and pavilion information

For Round Brilliants, crown and pavilion angles help describe how the upper and lower portions of the diamond are constructed.

Do not approve or reject a diamond using one proportion alone. The proportions interact, and the report should still be combined with visual evaluation.

14. Girdle

The girdle is the outer edge separating the crown from the pavilion.

A report may describe a range such as:

Thin to Medium, Faceted

Very thin areas can deserve additional durability attention. Very thick areas can retain weight without proportionally increasing face-up size.

A girdle description is not automatically a pass-or-fail result. Consider its location, variation, diamond shape, setting plan and the rest of the report.

15. Culet

The culet is the point or small facet at the bottom of the diamond.

The report might describe it as:

• None
• Very Small
• Small
• Medium
• Large
• Another applicable description

A larger open culet may be visible face-up, depending on the diamond and viewing conditions.

16. Clarity Plot

A plotted clarity diagram shows the approximate type and location of identifying clarity characteristics when a plot is included with the report.

The plot can help you:

• Understand which characteristics contributed to the grade.
• See whether important features are under the table or near the girdle.
• Compare the report with the physical diamond.
• Distinguish between two diamonds with similar headline grades.

The plot is a diagram, not a perfectly scaled photograph. It should be interpreted together with the key to symbols, clarity grade, comments and physical examination.

17. Key to Symbols

The key to symbols identifies the clarity characteristics recorded on the plot.

Examples can include:

• Crystal
• Feather
• Cloud
• Needle
• Pinpoint
• Cavity
• Chip
• Natural
• Indented natural
• Extra facet
• Polish line
• Surface graining

A characteristic’s name alone does not determine whether the diamond should be accepted or rejected.

For example, a feather can vary in size, position, visibility and orientation. A cloud can be minor or may deserve closer evaluation depending on its extent and relationship to the clarity grade.

Consider the complete report and the individual diamond.

18. Comments

The Comments section may contain important information that is not fully represented elsewhere.

Comments can refer to:

• Additional clarity characteristics
• Characteristics not shown on the plot
• Inscriptions
• Treatments
• Surface or internal graining
• Report limitations
• Other observations relevant to the individual diamond

Never skip this section.

A comment does not automatically mean the diamond is undesirable. It means the buyer should understand the observation and determine whether additional inspection is necessary.

19. Security and Digital Access

A printed page, PDF or screenshot should not be accepted without independent checking.

Use GIA’s official Report Check service to retrieve the associated record. If a QR code is present, confirm that it resolves to an official GIA-controlled destination.

Do not rely on:

• A supplier-hosted report image alone
• A screenshot of a GIA page
• A copied PDF
• A QR code leading to an unrelated domain
• A report number that has not been matched with the diamond

Existing legitimate reports may appear in different physical or digital formats. The verification process matters more than assuming that one format is automatically genuine.

A Practical GIA Report Example

Consider this fictional Round Brilliant report summary:

A careful buyer would not stop at “1.01 G VS2 Triple Excellent.”

The buyer would also:

1. Verify the report number.
2. Compare the measurements with the listed diamond.
3. Review the clarity plot and key to symbols.
4. Read the Comments section.
5. Check the inscription if one is recorded.
6. Inspect images or video for brightness, pattern and inclusion visibility.
7. Confirm the current condition of the diamond.
8. Evaluate price, availability and supplier terms separately.

Reading a Fancy-Shape Report

Consider a fictional Oval report:

The absence of a conventional overall GIA cut grade should not be filled with a seller-created “Excellent Cut” claim.

For an Oval, also evaluate:

• Length-to-width ratio
• Outline
• Shoulders
• Bow-tie appearance
• Facet pattern
• Face-up spread
• Inclusion visibility
• Video or physical appearance

The report provides essential specifications but does not communicate every visual characteristic.

How to Verify That the Report Matches the Diamond

Use this sequence:

1. Verify the report number

Retrieve the report through the official GIA Report Check.

2. Match the supplier listing

Compare:

• Shape
• Carat
• Colour
• Clarity
• Cut where applicable
• Polish
• Symmetry
• Fluorescence
• Measurements
• Report date
• Report number

3. Check the inscription

If an inscription is recorded, inspect it with appropriate magnification.

4. Match the physical measurements

Confirm that the dimensions are consistent with the report. Material inconsistency requires investigation.

5. Review identifying clarity characteristics

Compare visible or magnified characteristics with the plot and key to symbols where available.

6. Assess condition

Look for chips, abrasions, damage or evidence of alteration after the report date.

7. Compare the media and stone

Confirm that images and video show the same diamond. A report does not replace appearance assessment.

8. Verify the transaction separately

Confirm:

• Supplier identity
• Availability
• Price
• Invoice description
• Return terms
• Shipping
• Insurance
• Origin documentation where claimed

What a Standard GIA Report Does Not Tell You

A standard grading report does not independently determine:

• Retail price
• Wholesale price
• Replacement value
• Resale value
• Investment performance
• Ownership
• Seller reliability
• Current availability
• Customer preference
• Complete visual beauty
• Complete supply-chain compliance
• Mining origin

GIA offers a separate Diamond Origin Report service for qualifying diamonds submitted through the required process. A standard grading report should not be represented as mining-origin documentation.

For provenance guidance, read the Diamond Origin Report Guide.

GIA Report Verification Checklist

Before purchasing or presenting the diamond, confirm:

• Correct report type
• Report number verified on the official GIA website
• Report date reviewed
• Shape and cutting style match
• Measurements match
• Carat weight matches
• Colour grade matches
• Clarity grade matches
• Cut grade checked where applicable
• Polish checked
• Symmetry checked
• Fluorescence checked
• Proportions reviewed
• Girdle reviewed
• Culet reviewed
• Clarity plot reviewed where provided
• Key to symbols reviewed
• Comments read completely
• Inscription checked where recorded
• Images or video reviewed
• Physical condition checked
• Supplier listing matches the report
• Supplier identity verified
• Availability confirmed
• Price and commercial terms checked separately
• Origin documentation checked separately where claimed

Frequently Asked Questions

Review the Report Before Choosing the Diamond

A GIA report gives you a structured description of the diamond GIA examined. Read every field, verify the report through GIA’s official service and confirm that the report matches the stone being offered.

Then assess the diamond’s appearance, condition, price, provenance claims and transaction terms separately.

Browse Dalila Diamonds’ current inventory and request the complete report and current availability for any individual diamond you are considering.

Inventory, pricing and availability can change. Confirm the individual diamond and all transaction terms before making a commitment.