Moissanite
A gemstone made of silicon carbide, used as a diamond alternative, with a higher refractive index and more fire than diamond.
Properties
- Hardness of about 9.25 on the Mohs scale, below diamond at 10 but well above most gems.
- Refractive index of about 2.65 to 2.69, higher than diamond's 2.42.
- Dispersion of about 0.104, more than twice diamond's 0.044, which gives strong rainbow fire.
- Density lower than diamond, so a moissanite of the same size weighs less.
- Double refraction, which can make facet edges look slightly doubled at some viewing angles.
How it looks
Moissanite looks very bright and colourful, especially in sunlight. Some buyers love the extra fire, others prefer the cooler balance of diamond. Because its weight differs, moissanite is often sold by diameter or by diamond equivalent weight rather than by its own carat weight.
Rendering moissanite
Use a gem material with moissanite's IOR and dispersion, not diamond values. The higher dispersion produces more colour, which is accurate for this stone. Rendering a diamond with moissanite values, or moissanite with diamond values, misrepresents what the buyer receives.
In listings, name the stone clearly in the title and description. A render of a moissanite ring is accurate when it shows moissanite's real optical behaviour. Our diamond size chart also estimates moissanite weight at a given diameter.