Moissanite (silicon carbide) has become the most popular diamond alternative, offering diamond-like brilliance at a fraction of the cost. As the moissanite market grows, certification and grading standards are evolving. This guide explains how moissanite is certified and graded, and what buyers should look for.
What is Moissanite?
Moissanite is a gemstone composed of silicon carbide (SiC). Natural moissanite is extremely rare (found in meteorites), so virtually all moissanite on the market is laboratory-created. Moissanite has higher refractive index (2.65-2.69) than diamond (2.42), meaning it actually has more brilliance and fire (color sparkle) than diamond.
- Chemical composition - Silicon carbide (SiC)
- Hardness - 9.25 on Mohs scale (diamond = 10)
- Refractive index - 2.65-2.69 (higher than diamond 2.42)
- Dispersion (fire) - 0.104 (higher than diamond 0.044)
- Specific gravity - 3.22 (lighter than diamond 3.52)
- Origin - Virtually all is lab-created (natural is meteoritic and extremely rare)
Moissanite Grading Systems
Unlike diamonds, which have universal 4Cs grading, moissanite grading is less standardized. Several grading systems exist:
| Grading System | Used By | Scale |
|---|---|---|
| Diamond-equivalent (4Cs) | Charles & Colvard, many brands | D-Z color, FL-I3 clarity |
| Moissanite-specific | Some labs | Colorless/near-colorless, eye-clean |
| Brand-specific grades | Forever One, Forever Brilliant | Brand quality tiers |
| No grading | Cheap unbranded moissanite | None (buyer beware) |
Moissanite Color Grading
Moissanite color is typically graded using a diamond-equivalent scale, but with important differences. Moissanite naturally has a slight yellow or greenish tint, especially in larger sizes. High-quality moissanite is treated or grown to be colorless.
| Grade | Description | Availability |
|---|---|---|
| D-E-F (Colorless) | No visible color, premium quality | Forever One, premium brands |
| G-H-I (Near-colorless) | Slight tint, excellent value | Forever Brilliant, mid-range |
| J-K-L (Faint) | Noticeable warm tint | Budget moissanite |
| Unspecified | Variable quality | Cheap unbranded |
Charles & Colvard (the original moissanite patent holder) uses brand-specific grades: Forever One (colorless D-E-F), Forever Brilliant (near-colorless G-H-I), and Forever Classic (warmer J-K-L).
Moissanite Clarity
Lab-created moissanite is generally very clean (eye-clean to VS equivalent) because the controlled growth process minimizes inclusions. However, some moissanite may have:
Moissanite Cut Quality
Moissanite is cut to maximize its high dispersion (fire). The most popular cuts are:
Moissanite Certification Options
Brand Certificates
- Charles & Colvard - Certificate of authenticity with lifetime warranty
- Harro Gem - Certificate with cut quality assessment
- Other brands - Varying levels of certification documentation
Independent Lab Certificates
- IGI - Will certify moissanite, identifies as moissanite (not diamond)
- GIA - Can identify moissanite but does not grade it like diamonds
- NGTC - Certifies moissanite in China, identifies as synthetic moissanite
- Local labs - Many gem labs can identify and grade moissanite
Important: No major lab grades moissanite exactly like diamonds. Certificates typically identify the stone as moissanite/synthetic moissanite and may provide color/clarity grades, but these are not as standardized as diamond grading.
What to Look for in Moissanite Certification
- Identification - Clearly states "moissanite" or "synthetic moissanite" (not diamond)
- Color grade - D-E-F, G-H-I, or brand equivalent
- Clarity - Eye-clean or VS/SI equivalent
- Carat weight - Actual weight (or diamond equivalent weight/DEW)
- Measurements - Diameter and depth
- Cut grade - If provided (Excellent, Very Good, etc.)
- Origin - Lab-created (specify CVD or other method)
- Brand - Reputable brand (Charles & Colvard, Harro Gem, etc.)
- Warranty - Lifetime warranty against chipping/breakage
Moissanite vs Diamond Certification
| Factor | Moissanite | Diamond |
|---|---|---|
| Standardized grading | Less standardized | Universal 4Cs (GIA standard) |
| Color range | D-L (most are D-I) | D-Z |
| Clarity range | Mostly eye-clean to VS | FL-I3 |
| Certification cost | Included or low cost | 30-150 dollars per stone |
| Resale value | Low (10-30pct of purchase) | Higher (30-60pct of purchase) |
| Key certificate | Brand certificate + IGI optional | GIA/AGS/IGI certificate |
Common Moissanite Certification Issues
- Misrepresentation as diamond - Some sellers pass moissanite off as diamond; always check certificate
- Inflated color grades - Unbranded moissanite may claim D-F but actually be G-I
- No certificate - Cheap moissanite often sold without any certification
- Diamond Equivalent Weight (DEW) - Some sellers use DEW instead of actual weight; a 1ct DEW moissanite actually weighs ~0.88ct
- Treated moissanite - Some moissanite is coated or treated to improve color; ask about treatments
- Quality variation - Moissanite quality varies by manufacturer; brand matters
Buying Certified Moissanite: Tips
- Buy from reputable brands (Charles & Colvard, Harro Gem, or trusted manufacturers)
- Request a certificate of authenticity
- Verify color grade (ask for side-by-side comparison with certified diamonds)
- Check for eye-clean clarity (inspect under 10x loupe)
- Look for precision cutting (hearts and arrows pattern for rounds)
- Ask about warranty (reputable brands offer lifetime warranty)
- Be aware of DEW vs actual weight
- Compare prices across multiple sellers
- For wholesale, establish relationship with reliable moissanite suppliers in Wuzhou, China
Frequently Asked Questions
Is moissanite certified like diamonds?
Moissanite certification is less standardized than diamond grading. Reputable brands (Charles & Colvard, Harro Gem) provide certificates of authenticity with color/clarity grades. Independent labs like IGI can certify moissanite but identify it as moissanite, not diamond. No major lab grades moissanite exactly like diamonds. When buying moissanite, look for: clear identification as moissanite, color grade (D-E-F colorless is premium), eye-clean clarity, carat weight (not just DEW), and a warranty.
What is the best grade of moissanite?
The highest quality moissanite is colorless (D-E-F equivalent), eye-clean, and precision-cut. Charles & Colvard's 'Forever One' is the premium colorless grade. 'Forever Brilliant' (G-H-I near-colorless) offers excellent value - the slight tint is barely visible in most lighting. For jewelry, G-H-I grade moissanite provides the best balance of beauty and value, similar to how G-H color diamonds are the best value in diamonds.
What is Diamond Equivalent Weight (DEW) in moissanite?
DEW (Diamond Equivalent Weight) describes the size of a moissanite stone in terms of the diamond weight that would have the same dimensions. Because moissanite is less dense than diamond (specific gravity 3.22 vs 3.52), a moissanite of the same physical size weighs less. A 1-carat DEW moissanite actually weighs approximately 0.88 carats but looks the same size as a 1-carat diamond. Always check whether a seller quotes actual weight or DEW.
Can moissanite be certified by GIA or IGI?
IGI will certify moissanite and clearly identify it as synthetic moissanite, often with color and clarity grades. GIA can identify moissanite (distinguish it from diamond) but does not provide full 4Cs grading for moissanite. For most moissanite jewelry, a brand certificate (from Charles & Colvard or similar) is sufficient and more relevant than an independent lab certificate. For high-value pieces, IGI certification adds credibility.
More expert guides at GemManufacturer. Wholesale: service@holycome.com.
