We've sold moissanite in South Africa since 1999, so we know both stones well. Diamonds represent nature. Moissanite represents human understanding. Different territory — but the questions are fair, so here is how the two compare, round by round, including the round diamond wins.
3
Moissanite
1
Even
1
Diamond
Five rounds, scored below.
Same cut · same light
The same ideal round brilliant, lit the same way and rendered with the physics of light. The diamond returns crisp white sparkle; the moissanite splits more of the light into colour.
Renders, not photographs. Move the light yourself on the science page.
Moissanite's refractive index (2.65 vs 2.42) and dispersion (0.104 vs 0.044) are both higher than diamond's. Side by side under spotlighting, the moissanite throws visibly more rainbow fire. Some prefer diamond's subtler white sparkle — that's taste, not physics.
Diamond is a 10 on the Mohs scale, moissanite 9.25–9.5. Both are far beyond anything you'll encounter in daily life — only a diamond can scratch a moissanite. Moissanite has no cleavage planes, so it's actually less prone to chipping from a sharp knock.
A 1.00ct DEW colourless moissanite costs a few thousand rand. An equivalent D–F colour, eye-clean 1.00ct diamond costs well over R100,000 in South Africa. The gap reflects origin, not quality: one price carries geological scarcity, the other the cost of precision growth.
Moissanite
A few thousand rand
1.00 ct, colourless
Diamond
Well over R100 000
1.00 ct, colourless
Every gem-grade moissanite is lab-grown — there is no mined supply chain to audit, no provenance question to ask. If a fully traceable, conflict-free origin matters to you, moissanite is the only stone where that is true by definition.
Diamonds carry cultural weight and an (imperfect) resale market. Moissanite is bought to wear, not to trade. If heritage value or investment narrative matters to you, we'll say so plainly: buy the diamond.
Moissanite is about 13% lighter than diamond for its size, so we quote it in diamond-equivalent weight: the carat a diamond of the same size would be.
Not by eye. A trained gemmologist with a loupe can spot moissanite's double refraction; across a dinner table, nobody can. Standard diamond testers (thermal) actually read moissanite as diamond — only dedicated SiC testers tell them apart.
No. Moissanite is chemically stable silicon carbide — it cannot fade, cloud or change colour. The 'cloudy moissanite' myth comes from soap film on the pavilion; a 30-second clean restores full fire.
No — it's a different mineral with its own (superior) optical properties. It isn't sold as diamond and doesn't need to be: moissanite exceeds diamond on fire and brilliance, and is graded, certified and sold as exactly what it is — precision-grown silicon carbide.
Diamond Equivalent Weight. Moissanite is about 13% lighter than diamond per volume, so a stone the size of a 1ct diamond weighs ~0.88ct. DEW expresses size in the diamond terms everyone knows.
Questions we haven't covered? Call 010 100 8760 or email sales@moissanite.co.za.