Moissanite vs Diamond: A Complete Comparison

Moissanite and diamonds are the two most brilliant gemstones available for jewelry, and choosing between them is one of the most common decisions facing today's jewelry shoppers. This comprehensive comparison covers every factor that matters when making your choice.

Origins and Nature

Diamond

Diamonds are pure carbon crystals formed under extreme heat and pressure deep within the Earth over billions of years. Lab-grown diamonds have the same chemical composition and crystal structure as natural diamonds but are created in weeks rather than billions of years. For certification details, see our diamond certification guide.

Moissanite

Natural moissanite (silicon carbide) was first discovered in 1893 in a meteor crater by Henri Moissan. It is extraordinarily rare in nature — virtually all moissanite in jewelry today is lab-created. Moissanite has its own unique crystal structure and optical properties distinct from diamond.

Visual Comparison

Brilliance

Both stones are exceptionally brilliant, but they sparkle differently. Diamonds display a balance of white light (brilliance), rainbow flashes (fire), and scintillation (sparkle). Moissanite has a refractive index of 2.65 (vs diamond's 2.42), giving it slightly more brilliance. It also has significantly more fire (dispersion: 0.104 vs diamond's 0.044), producing more rainbow flashes — especially noticeable in larger stones and direct sunlight.

Color

Top-quality moissanite is near-colorless, comparable to G-H range diamonds. In some lighting conditions, moissanite may show a slight yellow or greenish tint. Premium "DEF" graded moissanite minimizes this. Diamonds are graded on a D-Z color scale, with the most valuable being completely colorless.

Clarity

Lab-created moissanite typically has excellent clarity, with few if any visible inclusions. Most moissanite on the market is eye-clean. Diamonds vary widely in clarity, and eye-clean natural diamonds command premium prices.

Physical Properties

Property	Diamond	Moissanite
Hardness (Mohs)	10	9.25
Toughness	Good	Excellent
Refractive Index	2.42	2.65
Dispersion (Fire)	0.044	0.104
Specific Gravity	3.52	3.21

Moissanite is the second hardest gemstone used in jewelry, making it extremely durable and scratch-resistant. Its excellent toughness means it resists chipping and breaking well.

Price Comparison

The most dramatic difference is price. A 1-carat lab-grown diamond typically costs $800-$2,000, while a natural diamond of similar quality costs $3,000-$8,000+. A comparable moissanite costs approximately $200-$600. For larger sizes, the savings become even more significant — a 2-carat moissanite might cost $400-$800 compared to $5,000+ for a lab-grown diamond and $15,000+ for a natural diamond.

Durability for Daily Wear

Both stones are excellent for daily wear, including engagement rings. Diamond's 10 Mohs hardness makes it virtually scratch-proof. Moissanite at 9.25 is also highly scratch-resistant — harder than sapphires, rubies, and all other common gemstones. Both will maintain their polish and brilliance for a lifetime.

Which Should You Choose?

Choose Diamond if:

• Traditional significance matters to you
• You prefer balanced brilliance without excessive rainbow flashes
• Resale value is a consideration
• You want the prestige associated with diamonds

Choose Moissanite if:

• You want maximum sparkle and fire
• investment is a primary consideration
• You want a larger stone for less money
• Ethical/environmental factors are important and you prefer non-diamond alternatives

Can People Tell the Difference?

To the untrained eye, moissanite and diamond look very similar in normal viewing conditions. In direct sunlight, moissanite's extra fire (rainbow sparkle) can be a distinguishing factor, especially in stones over 1 carat. Most casual observers cannot tell the difference. Jewelers can distinguish them using specialized testing equipment.

Explore our moissanite collection and diamond collection, and read our complete buying guide for more expert advice.