Moissanite vs cubic zirconia: what is the difference?
Moissanite is a real, very hard gemstone (silicon carbide, Mohs 9.25) that keeps its sparkle for life; cubic zirconia is a cheaper diamond simulant (Mohs 8 to 8.5) that scratches and clouds with years of wear. Moissanite also has more fire (dispersion 0.104 against about 0.06 for CZ) and a higher refractive index. CZ is fine for costume and fashion pieces; for anything worn every day or meant to last, moissanite is worth the extra cost.
Durability
Moissanite at Mohs 9.25 is harder than everything except diamond and resists everyday scratches. CZ at 8 to 8.5 slowly picks up surface wear from dust (which contains quartz, Mohs 7) and grit, which is why old CZ looks dull.
Sparkle
Moissanite: refractive index about 2.65 to 2.69 and dispersion 0.104, the rainbow fire it is known for. CZ: refractive index about 2.15 to 2.18 and dispersion around 0.06, bright but less lively. Diamond sits between them on fire (0.044) and between them on brilliance (2.42).
Weight and price
CZ is much denser (specific gravity about 5.6 to 6) than moissanite (3.22) or diamond (3.52), so a CZ feels heavy for its size. It is also far cheaper, which is why costume jewelry uses it.
Telling them apart
Moissanite shows doubled facet edges under a 10x loupe; CZ does not. A moissanite tester flags moissanite and reads CZ as a simulant.
Frequently Asked Questions
Is moissanite worth it over CZ?
For earrings, rings or anything worn daily, yes: it stays sharp and bright for decades. For a one-off outfit or costume piece, CZ is fine.
Is moissanite a fake diamond?
No. It is its own mineral, not an imitation of diamond. It only becomes a problem if someone sells it as diamond.
Keep reading
Amazon links are affiliate links (tag thegemtray-20): buying through them costs you nothing extra and supports the site. As an Amazon Associate we earn from qualifying purchases.