A lab-grown diamond certificate or grading report records identifying and quality information about an individual diamond. To read it correctly, begin with origin and report number, then review measurements, cut, color, clarity, carat weight, and any comments included by the issuing laboratory.
A report should be matched with the exact diamond and corresponding product page. It does not describe every part of the finished jewelry piece, and one product’s certificate should never be assumed to apply to another.
What is a lab-grown diamond certificate?
The word “certificate” is commonly used for a document that records the characteristics of a diamond. Depending on the issuer, the document may be called a grading report, laboratory report, or certificate.
The document generally describes the diamond at the time it was examined. It may include:
- A laboratory or certificate name
- A unique report number
- Laboratory-grown origin
- Diamond shape and cutting style
- Physical measurements
- Carat weight
- Color grade
- Clarity grade
- Cut-related information where applicable
- Polish and symmetry
- Fluorescence information where reported
- Comments, inscriptions, growth details, or treatment disclosures
Report formats differ. Do not assume that every issuing organization uses identical terminology, grading scales, layouts, or fields.
1. Identify the issuing laboratory
Begin by reading the name of the organization that issued the document. This tells you which laboratory’s terminology, format, and verification process you are reviewing.
ffulla certificate information is assigned by product. Applicable diamond listings may identify an IGI Certificate or NGTC Certificate. A GRC Certificate appears on selected sapphire jewelry and should not be assumed to apply to lab-grown diamond products.
| Certificate shown in the ffulla catalog | Where it may appear | What the buyer should do |
|---|---|---|
| IGI Certificate | Applicable made-to-order diamond engagement ring listings | Confirm it on the exact product page |
| NGTC Certificate | Applicable ready-to-ship diamond jewelry and ring listings | Confirm it on the exact product page |
| GRC Certificate | Selected sapphire jewelry | Do not treat it as a universal diamond certificate |
These are catalog patterns, not a rule to apply without checking. The certificate field on the exact product page remains the controlling product information.
2. Check the report number
A report number identifies the individual document and helps distinguish it from reports issued for other diamonds. Compare the number shown on the document with the information supplied for the stone.
If an inscription is listed, the report may record an identifying number or wording associated with the diamond. Do not assume that every diamond has the same type of inscription or that every inscription can be read without magnification.
3. Confirm laboratory-grown origin
Look for wording that identifies the diamond as laboratory-grown or lab-grown. Origin is one of the most important distinctions in the report.
A lab-grown diamond is real diamond material. It has the carbon crystal structure and essential physical properties that define diamond. Laboratory origin distinguishes how the crystal developed.
Read Are Lab-Grown Diamonds Real Diamonds? for a direct explanation of diamond material, origin, and simulants.
4. Read the shape and cutting style
Shape describes the diamond’s visible outline, such as round, oval, princess, pear, marquise, heart, or triangle. Cutting style describes the organization of its facets.
These terms should be compared with the product photographs and description. Shape should not be confused with the quality of the cut.
Learn more in Diamond Cut vs. Diamond Shape .
5. Compare the measurements
Measurements describe the diamond’s physical dimensions. Depending on the shape and report, they may include length, width, and depth.
Measurements help explain visible size and proportion. Two diamonds with the same carat weight can have different dimensions because their shapes and proportions distribute weight differently.
For elongated shapes, length and width also help describe whether the outline appears broad or slender. Use measurements alongside photographs and the actual appearance rather than treating one number as a complete quality judgment.
6. Read the carat weight
Carat is a unit of weight. One carat equals 200 milligrams. It does not directly state how large a diamond will look from above.
Confirm whether the value refers to the center diamond, an individual diamond, or another clearly labeled measurement. In multi-stone jewelry, product pages may present diamond information in different ways.
7. Review the color grade
Color grading records the presence or absence of visible body color within the grading system used by the issuing laboratory.
Lighting, diamond shape, carat weight, surroundings, and metal color can affect how color appears in a finished piece. Differences between nearby grades may also be subtle.
Match the grade on the report with the product page, but evaluate it as one part of the complete diamond rather than an isolated measure of beauty.
8. Review the clarity grade
Clarity evaluates internal and external characteristics. Internal features are commonly called inclusions, while external features may be called blemishes.
The grade reflects more than the number of characteristics. Their size, type, position, visibility, and effect on the diamond are also relevant to the assessment.
If a clarity diagram or comments section is included, use it to understand the recorded characteristics. Two diamonds with the same clarity grade do not necessarily contain identical features in identical positions.
9. Understand cut-related information
Cut affects how effectively a diamond interacts with light. A report may include cut-related grades or data such as proportions, polish, and symmetry, depending on the diamond shape and the report format.
Cut information should be read together with the diamond’s visible brightness, fire, scintillation, and contrast. A grading number or word cannot fully recreate the experience of seeing how the diamond responds to movement and light.
Review cut, color, clarity, and carat together in The 4Cs of Lab-Grown Diamonds .
10. Read polish, symmetry, and fluorescence
Polish
Polish concerns the quality of the diamond’s finished facet surfaces. Read the grade exactly as it appears on the report.
Symmetry
Symmetry considers the alignment and relationship of facets and the balance of the finished diamond. Outline symmetry is especially important when comparing elongated, pointed, or geometric shapes.
Fluorescence
When reported, fluorescence describes a diamond’s reaction under ultraviolet light. Do not use the fluorescence entry alone to judge the diamond’s overall appearance under ordinary lighting.
11. Read comments and disclosures
The comments section may contain information that does not fit within the main grading table. Depending on the report, this can include laboratory origin wording, growth method, post-growth treatment, inscriptions, or additional identifying details.
CVD and HPHT are the two principal lab-grown diamond methods. A report may identify the method when that information is included. Growth method and post-growth treatment are separate details and should not be assumed from one another.
Read CVD vs. HPHT Lab-Grown Diamonds for a comparison of the two growth processes.
What a diamond certificate does not tell you
A diamond report focuses on the stone and does not necessarily evaluate the entire jewelry piece. Unless specifically stated, it should not be assumed to determine:
- The comfort or fit of a finished ring
- The construction quality of the setting
- The suitability of a design for a particular lifestyle
- The value or meaning of the design to its wearer
- The current availability or delivery timing
- The complete terms of shipping, returns, warranty, or care
The product page should separately identify the jewelry’s setting, metal, dimensions, availability, and other specifications.
How to match a certificate with a product page
- Confirm the certificate name shown on the product page.
- Check the report or certificate number.
- Confirm that the stone is identified as laboratory-grown.
- Compare the diamond shape and cutting style.
- Compare measurements and carat weight.
- Compare color and clarity information.
- Read comments, inscriptions, and treatment disclosures.
- Check the setting, metal, size, and availability separately.
For example, the Hidden Heart Six-Prong Round Lab-Grown Diamond Engagement Ring is a made-to-order product whose listing identifies an IGI Certificate.
The Heart’s Embrace Ready-to-Ship Engagement Ring has its own product page and certificate information. Details from one version should not be applied automatically to another version or design.
What should you do if information does not match?
Do not guess which value is correct. If the report number, diamond shape, carat weight, color, clarity, or another identifying detail appears inconsistent with the product information, request clarification before completing the purchase.
Small formatting differences are not necessarily a conflict, but material differences in identity or grading information should be resolved.
Frequently asked questions
Do all lab-grown diamonds have certificates?
Not every product should be assumed to include the same documentation. Check the certificate field on the exact product page.
Does a certificate prove that a diamond is lab-grown?
The report should clearly identify laboratory-grown origin. Match the report with the exact diamond and corresponding product information.
Is a certificate number unique?
A report number is used to identify a particular document. Compare it with the information supplied for the individual diamond.
Does a certificate show the diamond’s size?
A report may provide physical measurements and carat weight. Carat measures weight, while measurements help describe physical dimensions.
Does the certificate grade the jewelry setting?
A diamond grading report generally focuses on the diamond. Review the product page separately for the setting, metal, dimensions, and availability.
Do all ffulla products use the same certificate?
No. Certificate information is product-specific. Applicable listings may identify IGI, NGTC, or GRC according to the exact product and stone type.
Is a certificate the same as an appraisal?
Not necessarily. A diamond grading report records characteristics of the stone. It should not automatically be treated as a monetary valuation or appraisal.
Compare diamond shape, the 4Cs, setting, metal, sizing, documentation, and availability before selecting an engagement ring.
Read the Engagement Ring Buying Guide →