What is moissanite?
Quick answer
Moissanite is lab-grown silicon carbide. It is 9.25 on the Mohs scale (diamond is 10), shows more rainbow fire than diamond, and costs around 10 to 15 per cent of a diamond at the same size. Natural moissanite exists but is too rare for jewellery, so almost every moissanite you see is grown in a lab.
The short answer
Moissanite is silicon carbide, a hard, transparent crystal. It was first found in 1893 by French scientist Henri Moissan, who identified the mineral in a meteorite crater in Arizona. Natural moissanite is too rare to use in jewellery, so commercial moissanite is grown in a lab.
The material is real. It is not a diamond, and it is not a cheap imitation. It is its own gemstone with its own properties, used widely in engagement rings, earrings and pendants. For a deeper look, read the full moissanite guide.
How it compares to diamond
The numbers below come up in almost every conversation about moissanite. For a longer comparison with photos and side-by-side examples, read moissanite vs diamond.
| Property | Moissanite | Diamond |
|---|---|---|
| Composition | Silicon carbide | Carbon |
| Hardness (Mohs) | 9.25 | 10 |
| Refractive index | 2.65 to 2.69 | 2.42 |
| Fire (dispersion) | 0.104 | 0.044 |
| Origin | Lab grown (natural moissanite is too rare) | Mined or lab grown |
| Approximate price | Around 10 to 15 per cent of an equivalent diamond | Premium |
Sparkle and fire
Moissanite has a higher refractive index than diamond (2.65 to 2.69 vs 2.42), so more light bends back to the eye. Its dispersion is also higher (0.104 vs 0.044), which means it splits white light into rainbow flashes more strongly. Most people describe the look as "more colourful sparkle" rather than the white-light flash of diamond.
In small stones the difference is hard to see. From about 1 carat and up, the rainbow fire becomes more obvious, particularly in sunlight or under spotlights. Some buyers love it. Some prefer the calmer, whiter look of diamond. Look at both in person before you decide.
Durability and daily wear
Moissanite is 9.25 on the Mohs hardness scale. Only diamond (10) is harder. Sapphire and ruby sit at 9. That puts moissanite firmly in the engagement-ring tier of stones that can handle everyday wear, hand washing, cleaning, cooking and travel.
It is heat resistant up to about 1,100 degrees Celsius, so jewellery repair and resizing do not damage it. Cleaning is the same as diamond: warm soapy water and a soft brush. Ultrasonic and steam are safe.
Colour grades
Modern moissanite is graded against the diamond colour scale. D, E and F are colourless. G, H and I are near colourless. LILY DIA uses DEF moissanite, which reads as colourless in everyday light. Some larger stones can show a very subtle warm tint under certain warm indoor lighting, the same way large diamonds show more colour than small ones.
Clarity is rarely an issue. Modern moissanite is grown clean and most stones are eye-clean across all sizes.
Price
A moissanite typically costs around 10 to 15 per cent of a diamond at the same size and similar appearance. A 1 carat moissanite is often priced closer to a 0.25 carat diamond. The gap grows with size, which is why many buyers choose moissanite when they want a larger centre stone for the budget.
Moissanite does not hold resale value the way diamond can. Buy it for the stone itself, not as an investment.
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Browse moissanite engagement ringsFrequently asked questions
- Is moissanite a diamond?
- No. Moissanite is silicon carbide. Diamond is carbon. Both are very hard, both sparkle, but they are different materials with different optical properties. Moissanite is not a fake diamond, it is its own gemstone.
- Will moissanite cloud or change colour?
- No. Moissanite holds its clarity and colour. Any cloudiness is dirt or oil on the surface and cleans off with warm soapy water. The stone itself does not change.
- Can people tell moissanite from diamond?
- Most people cannot tell by looking. Moissanite has more fire and shows double refraction under magnification, so a jeweller with the right equipment can identify it immediately. To the eye in everyday wear, they are very similar.
- How is moissanite made?
- Almost all moissanite is grown in a lab. Silicon and carbon are combined at very high temperatures to form silicon carbide crystals. The crystals are then cut and polished like diamonds. The growth process takes weeks rather than billions of years.
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