Moissanite vs Cubic Zirconia: Why CZ Doesn't Last

Cubic zirconia (CZ) is the cheapest diamond simulant on the market. It is also the one that looks worst a year later. Here is the difference in plain numbers.

Hardness

CZ sits at 8–8.5 on the Mohs scale and is brittle; it chips and abrades in daily wear. Moissanite is 9.25 and effectively scratch-proof in normal use.

Appearance over time

CZ is porous and absorbs skin oils, so it turns cloudy and yellow-grey within 6–18 months. Moissanite does not absorb oils — it only needs an occasional clean to look new.

Fire and brilliance

CZ has a low refractive index (2.17) and almost no fire. Moissanite's 2.65 index gives it the rainbow flashes that read as 'expensive' across a room.

Cost per year of wear

A $30 CZ ring replaced every year costs more over five years than one $99 moissanite ring that never needs replacing.