Moissanite vs diamond: what's the difference?
A moissanite gemstone costs significantly less than a diamond of comparable size – about £500–£600 per carat compared with £3,000–£5,000 for a 1 ct diamond. While both stones are durable and sparkly, diamonds are harder (Mohs 10 vs moissanite 9.25) and typically colourless, whereas moissanite may show a slight yellow or grey tint and displays more ‘rainbow’ fire.
The choice depends on budget and personal preference: moissanite offers a dazzling look for less with eco‑friendly origins, while diamonds are treasured for natural rarity, status and resale value.
Comparison overview
- Hardness: Diamond has a Mohs hardness of 10 while moissanite rates 9.25.
- Brilliance: Moissanite has a higher refractive index (2.65) giving more ‘rainbow’ fire; diamonds are prized for balanced white sparkle.
- Colour: Diamonds are usually colourless; moissanites can show slight yellow or grey tones.
- Price: Diamonds cost £3k–£5k per carat; moissanite is £500–£600 per carat.
- Weight: Moissanite weighs less than diamond, so a 1 ct moissanite looks larger than a 1 ct diamond.
- Origin: Diamonds are natural or lab‑grown carbon; moissanites are lab‑grown silicon carbide.
Pros and cons
- Moissanite pros: More affordable, eco‑friendly and ethical, with high brilliance and fire.
- Moissanite cons: May show a yellow or grey tint, not as hard as diamond, lacks natural rarity or resale value.
- Diamond pros: Highest hardness and durability, natural rarity and status, with greater resale value.
- Diamond cons: Expensive; mined diamonds may carry ethical and environmental concerns, and require regular cleaning.
FAQs
- Is moissanite a fake diamond? No, moissanite is a distinct gemstone made of silicon carbide; it isn't a diamond simulant although it looks similar.
- Will moissanite last as long as a diamond? Yes. With a Mohs hardness of 9.25, moissanite is durable enough for everyday wear.
- Why is moissanite cheaper than diamond? Moissanite is lab‑grown and less rare than natural diamond, so production costs are lower and prices are more affordable.