Moissanite (synthetic silicon carbide) looks extremely close to diamond, yet the two differ fundamentally in hardness, fire, thermal conductivity, and origin. Moissanite shows stronger fire at a fraction of the price, but it is slightly softer and has double refraction. Professional identification relies on a thermal tester and magnification, since the eye alone cannot fully separate them.

Key Parameter Comparison

• Composition and origin: Diamond is natural pure carbon; moissanite is lab-grown silicon carbide (SiC).
• Mohs hardness: Diamond is 10, the maximum; moissanite is 9.25, slightly below diamond but far above other simulants.
• Refractive index and fire: Moissanite has a refractive index of 2.65 and about 2.5 times the dispersion (fire) of diamond, showing more vivid rainbow flashes.
• Double refraction: Moissanite shows double refraction, so pavilion edges appear doubled under 10x magnification; diamond is singly refractive with sharp edges.

Four Identification Methods

• Thermal tester: Diamond conducts heat extremely well and triggers the tester; most moissanite reacts differently and needs a conductivity meter to confirm.
• 10x loupe: Moissanite shows doubled edges under the table and parallel needle-like inclusions; diamond often shows natural growth graining and original facets.
• Watch the fire: Moissanite flickers strongly with orange-green flashes; diamond fire is softer and more restrained.
• Certificate and girdle code: Genuine moissanite comes with a lab-grown certificate; diamond carries a grading report such as GIA, with a matching girdle laser code.

Buying Advice

Choose diamond for natural rarity and resale value; choose moissanite for high value, daily wear, and visual impact. Moissanite is widely used in silver and 18K gold jewelry for outstanding looks on a friendly budget. From a wear standpoint, moissanite at 9.25 on the Mohs scale resists everyday scratching, but it should still be kept away from drops and hard impacts. Diamond is the hardest material, yet it is also brittle and can chip under a sharp blow. Both stones should be cleaned regularly with a soft cloth and kept away from long-term contact with hand cream and sweat. MASCOT Jewelry supplies moissanite-set 925 silver pieces, clearly distinguishing stones and including descriptions, with OEM and ODM service exported to over fifty countries. Request samples from us.