Moissanite and cubic zirconia (CZ) are the two great diamond alternatives - but they are not the same product at different prices. One is a forever stone; the other is a fashion stone. Here is the honest comparison, number by number.
Sparkle: fire vs brilliance
Moissanite has a dispersion of 0.104 - more than double a diamond's - which produces its famous rainbow fire, and a refractive index of 2.65 for intense brilliance. CZ sits at 0.058 dispersion and 2.15 RI: bright and glassy-white, but flatter, with less rainbow flash. Side by side, moissanite looks alive; CZ looks clean and simple.
Hardness and lifetime
This is where they truly part ways. Moissanite scores 9.25 on the Mohs scale - second only to diamond - so it will not scratch, cloud or fade in a lifetime of daily wear. CZ scores 8-8.5: fine for occasional pieces, but in an everyday ring it gradually scratches and can turn cloudy within a few years. For a ring you never take off, that difference is everything.
Price
CZ is cheaper - often just a few dollars per stone, which is why it shines in fashion sets like our His and Hers band set. Moissanite costs more per carat but still a small fraction of a diamond - our 1 carat moissanite solitaire delivers the forever-stone experience at jewelry-box prices, especially at 60% OFF.
The verdict
Buying an engagement ring, a promise ring, or anything worn daily for years? Moissanite, no contest. Buying a fun set, a travel ring, or testing a style before committing? CZ is perfect for that. We compared moissanite against diamond itself in our moissanite vs diamond guide - and browse all rings to see both stones in action.
FAQ
Can people tell moissanite from CZ? In person, often yes - moissanite's rainbow fire is distinctive, especially in sunlight. CZ looks whiter and flatter.
Does moissanite get cloudy? No. Moissanite does not cloud with age; an oily film from skin can dull it temporarily, and warm soapy water restores the fire.
Is CZ bad quality? Not at all - it is the right stone for its job: beautiful, low-cost fashion sparkle. Just do not expect it to be a 10-year everyday stone.