When buying moissanite, you'll encounter certificates from several different gemological laboratories — most commonly the GRA (Gemological Research Association), and occasionally references to GIA (Gemological Institute of America) or IGI (International Gemological Institute). Understanding what each certificate means, which labs actually grade moissanite, and how to verify your certificate's authenticity is essential for making a confident purchase. This guide explains everything you need to know.
The GRA (Gemological Research Association): The Moissanite Standard
The GRA (Gemological Research Association) is the most widely used certification body for moissanite in the global market. GRA certificates are specifically designed for moissanite and other lab-created gemstones, using grading criteria and terminology adapted for these stones.
What GRA grades: Color (D through Z scale, adapted for moissanite), clarity (VVS1 through I2), cut, polish, symmetry, and fluorescence.
Verification: GRA certificates can be verified online using the certificate number on the GRA website.
Industry recognition: GRA is the most widely recognized moissanite certification in the industry. Most reputable moissanite retailers, including Moissanite Shine, provide GRA certificates with every stone.
What to look for: DEF color grade (colorless), VVS1 clarity grade, Excellent cut, Excellent polish, Excellent symmetry.
All Moissanite Shine stones come with a GRA certificate. For a step-by-step guide to reading your GRA certificate, see: How to Read a GRA Certificate.
The GIA (Gemological Institute of America): The Diamond Standard
The GIA is the world's most respected gemological laboratory and the gold standard for diamond certification. GIA certificates are widely recognized as the most reliable and consistent diamond grading reports available. However, there is an important distinction for moissanite buyers:
Does GIA grade moissanite? The GIA does not issue standard grading reports for moissanite. The GIA has historically declined to grade moissanite on its standard diamond grading scale, as moissanite is a distinct gemstone with different optical properties. Some GIA-affiliated labs may issue identification reports for moissanite (confirming the stone's identity), but these are not the same as a full grading report.
What this means for buyers: If a seller claims their moissanite has a "GIA certificate," ask for clarification. A GIA identification report confirms the stone is moissanite; it does not grade its color, clarity, or cut on the standard scale. A GRA certificate is the appropriate certification for moissanite.
The IGI (International Gemological Institute): Lab-Grown Diamond Specialist
The IGI is one of the world's largest gemological laboratories and has become a major player in the lab-grown diamond certification market. IGI certificates are widely used for lab-grown diamonds and are generally well-regarded in the industry.
Does IGI grade moissanite? IGI does issue grading reports for moissanite in some markets, though this is less common than GRA certification. IGI moissanite reports use similar grading criteria to GRA reports.
IGI vs. GRA for moissanite: Both GRA and IGI are legitimate certification options for moissanite. GRA is more widely used and more specifically focused on moissanite; IGI has broader recognition in the lab-grown diamond market. Either certificate from a reputable lab is a valid verification of your stone's quality.
What to watch for: Verify that any IGI certificate is for moissanite specifically, not for a lab-grown diamond. The two stones have different optical properties and different grading criteria.
Red Flags: Certificates to Be Skeptical Of
⚠️ "In-house" certificates: Some retailers issue their own certificates rather than using an independent lab. These certificates have no independent verification and should be treated with skepticism.
⚠️ Unverifiable certificate numbers: Any legitimate certificate from GRA or IGI can be verified online. If the certificate number doesn't appear in the lab's database, the certificate may be fraudulent.
⚠️ "GIA certified moissanite": As noted above, GIA does not issue standard grading reports for moissanite. This claim should prompt further investigation.
⚠️ No certificate at all: Any reputable moissanite retailer should provide a certificate from an independent lab. No certificate is a significant red flag.
The Bottom Line
For moissanite, the GRA certificate is the industry standard — the most widely used, most specifically designed, and most easily verified certification for moissanite stones. All Moissanite Shine stones come with a GRA certificate, and every certificate can be verified online using the certificate number.
Explore our collection — every stone DEF color, VVS1 clarity, GRA-certified, and backed by our Lifetime Gemstone Warranty.
🛡️ Lifetime Gemstone Warranty — Your stones are protected forever.
⬆️ Lifetime Upgrade Program — Upgrade your stones or metal anytime.
✏️ Request a Custom Design — Make it uniquely yours.
Related guides:
How to Read a GRA Certificate Step by Step
GRA Certificate Explained
How Moissanite Is Graded Inside the GRA Lab
Moissanite Color Grades Explained
Moissanite Clarity Grades Explained