Lab-Grown Diamond Grading Explained
An IGI certificate is an independent grading report from the International Gemological Institute — the world's largest certifier of lab-grown diamonds. It objectively documents a diamond's cut, color, clarity, carat weight, growth method, and laser inscription number, with no commercial interest in the stone's value. Every DEEVE lab-grown diamond includes a verified IGI certificate with online authentication at igi.org.
Quick Answer: 5 Key Facts About IGI Certificates
- IGI is the #1 certifier for lab-grown diamonds — accepted by major retailers and insurers worldwide
- The certificate grades the 4Cs — cut, color, clarity, and carat weight, plus polish, symmetry, and fluorescence
- Growth method is disclosed — CVD or HPHT is stated on every lab-grown diamond report
- Verify online in 60 seconds — enter the report number at igi.org to confirm authenticity
- DEEVE selects D–G color, VS2+ clarity, Excellent–Very Good cut — every certificate verified before acceptance
✓ Every DEEVE lab-grown diamond includes a verified IGI certificate with online authentication.
The 4Cs: What IGI Grades
IGI evaluates every diamond across four quality dimensions — the industry-standard 4Cs framework created by GIA and used by all major gemological laboratories.
Cut
How well the diamond's facets interact with light. Grades: Excellent, Very Good, Good, Fair, Poor. Cut is the most important factor for brilliance.
Color
Absence of color in white diamonds. Graded D (colorless) to Z (light yellow). D–G is the range DEEVE selects for near-colorless to colorless appearance.
Clarity
Internal characteristics (inclusions) and surface features (blemishes). Graded FL to I3. VS2 and above means inclusions are invisible to the naked eye.
Carat
The diamond's weight. 1 carat = 0.2 grams. Carat affects size but should always be evaluated alongside cut quality for optimal appearance.
Sample IGI Certificate
This is what an IGI Laboratory Grown Diamond Report looks like. Every field is explained in detail below.
Sample IGI Laboratory Grown Diamond Report — report number and personal details redacted for privacy.
What's on the Certificate
- Report NumberUnique ID for online verification and insurance records
- Shape & Cut Stylee.g. Round Brilliant, Oval, Princess, Cushion
- MeasurementsPrecise dimensions in millimeters
- Cut GradeExcellent / Very Good / Good
- Color GradeD through Z scale
- Clarity GradeFL, IF, VVS1, VVS2, VS1, VS2, SI1, SI2, I1–I3
- Carat WeightWeight to two decimal places
- Polish & SymmetrySurface finish and facet precision grades
- FluorescenceReaction to UV light: None, Faint, Medium, Strong
- Growth MethodCVD or HPHT — how the lab-grown diamond was produced
- Post-Growth TreatmentDiscloses HPHT annealing or other treatments if applied
- Clarity PlotDiagram showing the location and type of any inclusions
- Laser InscriptionReport number engraved on the diamond's girdle
How to Verify Your Certificate
- Locate the IGI Report Number printed on your certificate
- Visit igi.org/Verify-Your-Report and enter the number
- The IGI database displays the original grading details — confirm they match your certificate
- Under 10× magnification, check the laser inscription on the diamond's girdle matches the report number
DEEVE's Diamond Standards
- Color: D–G range (colorless to near-colorless)
- Clarity: VS2 or higher — inclusions invisible to the naked eye
- Cut: Excellent to Very Good — maximum light performance
- Certification: Every certificate verified through IGI's official portal before acceptance
- Laser inscription: Confirmed to match certificate number on every stone
- Treatment disclosure: Any post-growth treatments are disclosed on the certificate
Frequently Asked Questions
Is IGI as good as GIA?
IGI and GIA are both reputable, internationally recognized gemological laboratories. GIA is the most widely recognized globally and is considered the industry standard for natural diamonds. IGI is the most widely used certification for lab-grown diamonds and offers comparable grading at a lower cost. For lab-grown diamonds, IGI certification is accepted by major retailers and insurers worldwide. Both are trustworthy — the key is buying any certified diamond over an uncertified one. Read the full GIA vs IGI vs GCAL comparison →
What clarity grade should I look for?
VS2 or higher means inclusions are invisible to the naked eye — this is the best value for most buyers. VVS1 and IF grades are premium but the difference from VS2 is invisible without magnification. DEEVE selects VS2 and above for all lab-grown diamonds. Avoid I1–I3 grades where inclusions may be visible and can affect durability. Read: Diamond Clarity & Quality Guide →
What does the growth method field mean on my certificate?
CVD (Chemical Vapor Deposition) and HPHT (High Pressure High Temperature) are the two methods used to grow lab-grown diamonds. IGI discloses the growth method on every lab-grown diamond certificate. Neither method produces a better diamond — quality depends on the certified 4Cs grades. Both have identical hardness (Mohs 10) and optical properties. Read: CVD vs HPHT Explained →
What does "post-growth treatment" mean on an IGI certificate?
Some lab-grown diamonds undergo HPHT annealing after initial growth to improve color by reducing yellow or brown tones. This treatment is permanent, stable, and does not affect durability. IGI discloses it in the Comments section of the certificate. A treated diamond is still a real diamond — treatment disclosure is a sign of transparency, not a defect.
Does an IGI certificate affect resale or insurance value?
Yes. An IGI certificate provides objective, third-party documentation of a diamond's characteristics that is recognized by insurers, appraisers, and resellers worldwide. Certified diamonds are easier to insure and command higher resale values than uncertified stones. The laser inscription linking the physical diamond to the certificate provides additional security against substitution.
Where can I learn more about reading an IGI certificate?
For a complete walkthrough of every field on an IGI lab-grown diamond certificate — including how to read the 4Cs, verify the laser inscription, and compare IGI with GIA and HRD — see our full guide. How to Read an IGI Lab Grown Diamond Certificate — Complete Guide →
Related Resources
Diamond Education Hub → IGI Certificate — Full Guide → GIA vs IGI vs GCAL → Lab-Grown Buying Guide → CVD vs HPHT → Diamond Clarity & Quality Guide → Shop Diamond Jewelry →Browse IGI-certified lab-grown diamonds set in solid 14K gold — with lifetime warranty and free shipping to Canada and the US.
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