Moissanite vs diamond: the differences you can actually see

Both are colourless, both are hard, both are certified. They do not look identical, and the difference is not a matter of quality — it is optics.

The numbers

What that means in daylight

Dispersion is the splitting of white light into colour. At 0.104, moissanite throws more than twice the coloured fire of diamond — visible as flashes of blue, green and orange when the stone moves. In a jewellery store's spotlights this reads as brilliance. In direct sun it can read as “rainbow”, which some people love and others do not.

Diamond's fire is subtler and whiter. That restraint is part of why it reads as expensive to many buyers.

Hardness and daily wear

Diamond is 10; moissanite is 9.25. Both resist scratching from everyday materials — the hardest common dust is around 7. Moissanite is more brittle than diamond, so it can chip at the girdle if struck; a bezel setting protects it better than thin prongs.

Colour and clarity

Moissanite is grown in D colour and graded VVS in-house; older stones with a yellow or green tint are still in the secondary market. Lab-grown diamond is graded on the 4Cs and can be bought at any grade, which means you can trade colour for size.

Price

At the same millimetre size, moissanite typically costs a tenth of a comparable lab-grown diamond, and a fraction of a mined one. The gap is largest above 1 ct.

Which should you buy?

• Moissanite if you want maximum sparkle per dollar, a stone that is visually larger than its price, and you like coloured fire.
• Lab-grown diamond if you want diamond optics and the resale-adjacent confidence of an IGI report, and the budget allows.
• Neither if you want a stone that holds value — that is a mined diamond, and it is a different purchase.

We make both, in the same settings, so the comparison is honest. Browse moissanite or browse lab-grown diamond.