Two of the most popular choices for engagement rings today — lab grown diamonds and moissanite — are frequently compared, often confused, and occasionally misrepresented by sellers with a stake in one or the other. This guide gives you the honest comparison: what they actually are, how they differ, what each costs, and which is the right choice for an engagement ring.
The short answer: they are genuinely different materials with different properties, different appearances under certain conditions, and different price points. Neither is objectively "better" — but for most buyers shopping for a diamond engagement ring, they are not interchangeable.
What Is a Lab Grown Diamond?
A lab grown diamond is a real diamond — pure carbon atoms arranged in a cubic crystal lattice, created in a laboratory environment rather than mined from the earth. It is chemically, physically, and optically identical to a mined diamond. The Federal Trade Commission recognizes lab grown diamonds as real diamonds, and grading laboratories like IGI and GIA certify them using the same 4 Cs standards as natural stones.
Lab grown diamonds cost 50%–70% less than comparable mined diamonds because they are produced through an industrial process rather than extracted through expensive mining operations. The lower price reflects a different origin and more abundant supply — not lower quality.
For a complete explanation: What is a lab grown diamond?
What Is Moissanite?
Moissanite is a different gemstone entirely. It is silicon carbide (SiC) — a compound of silicon and carbon — rather than pure carbon like diamond. It was first discovered in 1893 by French chemist Henri Moissan in fragments of a meteorite in Arizona, which is how it got its name. Natural moissanite is extraordinarily rare; virtually all moissanite sold in jewelry today is laboratory-created.
Moissanite is not a diamond and does not claim to be one. It is a distinct gemstone with its own properties — some similar to diamond, some notably different. It is marketed as a diamond alternative rather than a diamond substitute, and reputable moissanite sellers are clear about this distinction.
Moissanite has been available as a jewelry gemstone since the late 1990s, when Charles & Colvard (its primary producer) began commercial production. It has grown significantly in popularity as an alternative to both natural and lab grown diamonds.
The Key Differences
Chemical Composition
| Property | Lab Grown Diamond | Moissanite |
|---|---|---|
| Chemical formula | C (pure carbon) | SiC (silicon carbide) |
| Crystal structure | Cubic (isometric) | Hexagonal |
| Hardness (Mohs) | 10 — hardest material on earth | 9.25 — extremely hard |
| Refractive index | 2.42 | 2.65–2.69 |
| Dispersion (fire) | 0.044 | 0.104 — more than double diamond |
| Birefringence | None | Present — causes doubling effect |
| Certified as diamond | Yes (IGI, GIA, FTC) | No — it is not a diamond |
Appearance: Do They Look the Same?
This is where the comparison gets interesting — and where moissanite sellers and diamond sellers often talk past each other.
Brilliance
Lab grown diamonds and moissanite both produce beautiful white light return. In terms of overall brightness, they look similar to the casual observer at a glance. Side by side in ideal conditions, a well-cut diamond may have slightly more balanced, uniform brilliance — but this difference is subtle and requires careful comparison.
Fire (Rainbow Flashes)
This is the most significant visual difference between the two. Moissanite has a dispersion value of 0.104 — more than double the 0.044 of diamond. This means moissanite produces significantly more colorful spectral flashes — rainbow fire — than diamond, particularly in direct sunlight or bright lighting.
Whether this is an advantage or disadvantage is entirely a matter of personal taste:
- Some people find the rainbow fire of moissanite extraordinarily beautiful — more colorful and lively than a diamond
- Others find it excessive — too much color, too obviously "not a diamond," particularly in bright light or photography
- People who know diamonds well can often identify moissanite in bright light specifically because of the high fire
In subdued lighting — indoors, evening settings — moissanite and lab grown diamonds are difficult for most people to distinguish. In bright sunlight or flash photography, the difference in fire becomes more apparent.
The Doubling Effect
Moissanite is birefringent — meaning it has two different refractive indices depending on the direction light travels through the stone. This creates a subtle "doubling" of the facet edges inside the stone when viewed from certain angles under magnification. This effect is not visible to the naked eye at normal viewing distances in a well-cut stone but can be seen under 10x magnification.
This is one way gemologists and experienced jewelers identify moissanite — though it requires magnification and trained observation.
Color
Early moissanite had a slight green, yellow, or gray tint in certain lighting conditions that made it visibly different from a colorless diamond. Modern "Forever One" moissanite (Charles & Colvard's premium colorless grade) has addressed this significantly — top-grade moissanite today is very white and comparable to near-colorless diamonds in most lighting.
Lower-grade moissanite may still show slight color tints in certain light. If considering moissanite, choose colorless (D-E-F equivalent) grade to minimize this.
Durability Comparison
| Property | Lab Grown Diamond | Moissanite |
|---|---|---|
| Hardness (Mohs) | 10 — maximum | 9.25 — extremely hard |
| Scratch resistance | Highest possible | Excellent — second only to diamond |
| Chip resistance | High (can chip at sharp edges) | High (similar to diamond) |
| Heat resistance | Excellent | Excellent |
| Chemical resistance | Excellent | Excellent |
| Suitable for daily wear | Yes — indefinitely | Yes — indefinitely |
Both lab grown diamonds and moissanite are extremely durable — more than adequate for daily wear in an engagement ring. The hardness difference (10 vs 9.25) is real but practically insignificant for most wearers. Both stones will remain scratch-free and beautiful with normal jewelry care for a lifetime.
Moissanite is not a fragile or low-quality gemstone in terms of durability. It is one of the hardest and most durable gemstones available.
Price Comparison
Price is where moissanite has its clearest advantage — and where the comparison is most directly useful.
| Stone | Approximate Price (1ct equivalent) | Notes |
|---|---|---|
| Natural diamond (1ct, G, VS2, Excellent) | $4,000–$7,000 | Price varies significantly by exact specs |
| Lab grown diamond (1ct, G, VS2, Excellent) | $800–$1,500 | IGI certified |
| Premium moissanite (1ct equivalent, colorless) | $300–$600 | Charles & Colvard Forever One or equivalent |
| Standard moissanite (1ct equivalent) | $100–$300 | May show slight color tints |
Moissanite is significantly less expensive than lab grown diamonds. For buyers with a very tight budget who want the largest possible stone, moissanite offers more size for less money than any diamond option.
However, the gap between lab grown diamonds and moissanite is considerably smaller than the gap between natural diamonds and moissanite. A lab grown diamond is approximately 2–5 times the price of equivalent moissanite — still a real difference, but not the 5–10x difference that exists between natural diamonds and moissanite.
The Certification Difference
This is an important practical distinction often overlooked in comparisons.
Lab grown diamonds are graded and certified by independent gemological laboratories — IGI and GIA — using the same 4 Cs system as natural diamonds. You receive a certificate that independently documents the exact cut, color, clarity, and carat of your specific stone. This certificate has value for insurance, resale, and peace of mind.
Moissanite is not graded by IGI or GIA using the diamond 4 Cs system. Moissanite is typically sold with a manufacturer's certificate from Charles & Colvard or the seller's own documentation, but not an independent grading report of the type available for diamonds. Quality grades for moissanite (colorless, near-colorless, etc.) are defined by the manufacturer rather than by an independent third party.
This doesn't mean moissanite is unreliable — reputable sellers represent their product accurately. But the independent third-party verification that an IGI certificate provides for a lab grown diamond does not have a direct equivalent in moissanite.
Which Do Diamond Testers Identify?
Standard thermal conductivity diamond testers — the handheld devices used in many retail jewelry stores — cannot distinguish lab grown diamonds from natural diamonds, because both are real diamonds.
Interestingly, moissanite also passes standard thermal conductivity diamond testers, because its thermal conductivity is similar enough to diamond to register as positive. This means moissanite will "pass" a basic diamond test — which has led to some confusion and, occasionally, misrepresentation.
Advanced electrical conductivity testers can distinguish moissanite from diamond (they test differently on the electrical test). Jewelers who need to identify moissanite specifically use these more advanced tools or gemological microscopes.
For buyers: this means neither lab grown diamonds nor moissanite will be identified as "not diamond" by a basic tester — but the two can be distinguished by advanced tools if needed.
Who Should Choose a Lab Grown Diamond?
- Anyone who wants a real diamond. If the diamond itself — real, certified, with the properties, grading, and identity of a diamond — matters, a lab grown diamond is the answer. Moissanite is a beautiful gemstone, but it is not a diamond.
- Those who want independent certification. An IGI certificate provides independent, third-party documentation of exactly what you're buying. This matters for insurance, resale, and confidence in the purchase.
- Those who prefer diamond's specific optical properties. If the slightly more subdued, balanced fire of a diamond — rather than the higher rainbow dispersion of moissanite — is preferred, lab grown diamond is the right choice.
- Those who want maximum long-term value. Lab grown diamonds, while declining in resale value, still have a more established secondary market than moissanite.
- Those with a budget of $1,500 or more for the center stone. Lab grown diamonds become very compelling value at this price point — a 1ct+ Excellent-cut lab grown diamond at $1,000–$1,500 is a genuinely impressive stone.
Who Should Choose Moissanite?
- Those with a very tight budget who want maximum size. Moissanite provides more visual presence per dollar than any diamond option. If budget is the primary constraint and stone size matters most, moissanite is worth serious consideration.
- Those who love moissanite's fire specifically. Some people genuinely prefer the higher rainbow dispersion of moissanite — they find it more beautiful than diamond's more restrained fire. If she loves colorful flash, moissanite may actually suit her better.
- Those who are transparent about the choice. Moissanite is a beautiful gemstone on its own terms. Buying it knowingly and proudly — not as a diamond substitute but as a distinct choice — is completely valid.
- Those who specifically don't want a diamond for ethical reasons. While lab grown diamonds address most mining ethics concerns, some buyers prefer to avoid diamonds entirely. Moissanite is a coherent choice in this context.
Complete Side-by-Side Comparison
| Factor | Lab Grown Diamond | Moissanite |
|---|---|---|
| Is it a diamond? | Yes | No — different gemstone |
| Hardness | 10 (Mohs) | 9.25 (Mohs) |
| Brilliance | High — diamond standard | High — similar overall |
| Fire (rainbow flashes) | High | Very high — more than diamond |
| Color (top grade) | D–Z graded scale | Colorless, near-colorless grades |
| Independent certification | Yes — IGI / GIA | Manufacturer certificate only |
| Price (1ct equivalent) | $800–$1,500 (lab grown) | $300–$600 (premium grade) |
| Passes basic diamond tester | Yes | Yes (thermal test) |
| Daily wear durability | Excellent | Excellent |
| Resale market | Limited but exists | Very limited |
| Insurance documentation | Strong — IGI certificate | Weaker — no independent cert |
| Ethical sourcing | Fully traceable — lab origin | Fully traceable — lab origin |
Frequently Asked Questions
Can you tell the difference between moissanite and a lab grown diamond?
In most everyday settings — indoors, typical room lighting, normal viewing distance — most people cannot reliably tell the difference. In bright sunlight or flash photography, moissanite's significantly higher fire (rainbow dispersion) becomes more apparent and is one of the ways experienced observers identify it. Under gemological magnification, the doubling effect in moissanite is distinctive. A jeweler with an advanced tester can identify moissanite quickly and reliably.
Is moissanite considered fake?
No — moissanite is a real gemstone with genuine properties. It is not a fake diamond; it is a different stone. The distinction matters: moissanite is only "fake" if it's sold as a diamond, which reputable sellers never do. Bought and worn knowingly as moissanite, it's a legitimate gemstone choice with no pretense attached.
Will moissanite look the same as a diamond in photos?
In many photos — particularly in warm or indoor lighting — moissanite and lab grown diamonds look very similar. In bright natural light or with flash photography, moissanite's higher fire often creates more rainbow color in the image, which experienced observers recognize. Engagement photos in bright outdoor light sometimes reveal this difference more clearly than everyday wear does.
Does moissanite get cloudy over time?
No — moissanite is chemically stable and does not cloud, fade, or lose its clarity over time. Like a diamond, the only thing that makes moissanite look dull is surface buildup from oils and lotions, which is easily cleaned with warm water and mild soap.
Which is better for an engagement ring — lab grown diamond or moissanite?
It depends on what matters most. If being a real diamond matters — for reasons of tradition, certification, identity, or personal significance — a lab grown diamond is the answer. If budget is the primary constraint and size is the priority, moissanite offers more visual presence per dollar. Both are durable and beautiful. The choice is genuinely personal, not objectively settled.
Can I insure a moissanite engagement ring?
Yes. Moissanite rings can be insured, though the documentation differs from a diamond ring. Without an IGI or GIA certificate, you'll typically rely on a purchase receipt and an independent appraisal to document the ring's value. Specialist jewelry insurers handle moissanite routinely. The insured value will reflect the replacement cost of a comparable moissanite stone rather than diamond pricing.
Our Recommendation at Anjays Designs
At Anjays Designs, we specialize in lab grown diamonds — not because moissanite isn't beautiful, but because we believe lab grown diamonds offer the best combination of quality, certification, identity, and value for engagement ring buyers.
A lab grown diamond gives you a real diamond — independently certified by IGI, graded to the same standards as any natural stone, with the optical properties and identity of diamond — at 50%–70% less than an equivalent mined stone. For most buyers, that combination is more compelling than moissanite's lower price, particularly when the per-carat gap between lab grown diamonds and moissanite is much smaller than it once was.
That said, we respect that moissanite is a valid choice for buyers who prioritize maximum size on a very tight budget or who prefer moissanite's specific optical character. What matters most is that you make the choice that's right for your relationship and your values — with full information about what each option actually is.
Browse our IGI-certified lab grown diamond engagement rings →
Questions about lab grown diamonds vs moissanite for a specific ring or budget? Contact us — we're happy to help you think it through.