Moissanite is a brilliant, colourless gemstone made of silicon carbide, almost as hard as diamond and with even more fire (rainbow sparkle). Natural moissanite is extremely rare, so gem moissanite is made in a laboratory. It is a popular, affordable alternative to diamond for rings and jewellery, and we sell it loose by shape, with every size given in millimetres, carats and ratti.
At a glance · Is this stone for you?
Moissanite at a glance
- 💎 Looks like diamond, costs far less
- 🌈 More fire than diamond
- 💪 9.25 on the Mohs scale
- 🔬 Made in a laboratory; natural is extremely rare
- 💍 Ideal for everyday rings
- 📏 Sold in mm, carats and ratti
| Also called | Silicon carbide (SiC) |
|---|---|
| What it is | Silicon carbide gemstone, made in a laboratory |
| Colour | Colourless (D–F range) and many fancy colours |
| Hardness | 9.25 on the Mohs scale (diamond is 10) |
| Sparkle | Higher refractive index and fire than diamond |
| Weight | About 10% lighter than a diamond of the same size |
| Sizes | Chosen by millimetre; we also show carats and ratti |
| Water | Safe to wash; very durable |
Let's start simple
What is moissanite?
Moissanite is silicon carbide. It was discovered in 1893 by French chemist Henri Moissan in fragments of a meteorite crater in Arizona; he first thought he had found diamonds. Natural moissanite is so rare that every moissanite in jewellery today is grown in a lab, with the same chemistry and hardness as the natural mineral.
It is not a fake diamond or a diamond simulant made of glass: it is its own gemstone, with its own sparkle, and it is hard enough to last a lifetime of daily wear.
"Moissanite isn't trying to be a diamond. It is simply a brilliant gem in its own right."
Why people choose it
What is moissanite used for?
The main reasons people choose moissanite:
💍 Engagement and wedding rings
The look of diamond at a fraction of the price.
🌈 Maximum sparkle
Its strong fire shows rainbow flashes in light.
💪 Everyday durability
Hard enough for rings worn every day.
🌱 Made in a laboratory
No mining of the gem itself.
💰 Bigger for the budget
Larger stones become affordable.
🎨 Custom jewellery
Loose stones for your own designs or our bespoke service.
For absolute beginners
How do I choose moissanite?
Loose moissanite is chosen by shape, size and colour.
🔷 Pick a shape
Round, oval, cushion, pear, emerald, princess, heart and more.
📏 Choose the size in mm
Moissanite is cut to millimetre sizes; carats and ratti are shown for reference.
📱 See it at actual size
Our size chart can match your screen to a card or coin so you see the true size.
⚖️ Ratti for reference
Ratti is shown because many Indian buyers think in ratti; our ratti guide explains it.
🎨 Choose a colour
Colourless, or a fancy colour.
💍 Set it
In gold, silver or platinum, or through our bespoke service.
Care
How do you clean and care for moissanite?
Moissanite is very durable and keeps its sparkle with simple cleaning.
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Warm water and mild soap
Soak for a few minutes.
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Soft toothbrush
Brush gently behind the stone, where lotion and dust collect.
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Rinse and dry
With a lint-free cloth.
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Store it apart
It can scratch softer gems and metal, so keep it in its own pouch.
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Check settings yearly
The stone is tough; the prongs holding it need checking.
Size guide
How big is it really?
Because moissanite is a little lighter than diamond, compare by millimetre, not carat. A rough guide for round moissanite:
- 5 mm looks like a half-carat diamond.
- 6.5 mm looks like a one-carat diamond.
- 7.5 mm looks like a 1.5-carat diamond.
- 8 mm looks like a two-carat diamond.
- 9 mm looks like a three-carat diamond.
💡 Use the "See actual size" tool on any moissanite product page to check on your own screen.
Moissanite myths, cleared up
Myth: "Moissanite is fake diamond."
It is a different gemstone, not a diamond imitation like glass or cubic zirconia.
Myth: "Moissanite gets cloudy over time."
It does not change; any cloudiness is dirt and cleans off.
Myth: "Moissanite is the same as cubic zirconia."
CZ is much softer (about 8) and scratches over time; moissanite is 9.25.
Myth: "A diamond tester can always tell."
Basic thermal testers often read moissanite as diamond; a dedicated moissanite tester can tell them apart.
What to expect
How does moissanite look when worn?
Most people find moissanite looks like a very bright diamond. In strong light, especially sunlight, it shows more rainbow flashes than diamond; some people love this, others prefer diamond's whiter sparkle. Our moissanite vs diamond guide compares them in detail.
"In candlelight, moissanite throws rainbows."
Popular shapes
Which moissanite shape suits you?
A quick guide to the most popular cuts:
Round
Maximum sparkle; the classic choice.
Oval
Looks larger for its weight and lengthens the finger.
Cushion
Soft, romantic, vintage feel.
Pear
Elegant and distinctive.
Emerald cut
Clean, step-cut lines; a glassy, refined look.
Heart
A romantic gift shape.
Moissanite: questions people ask
Is moissanite a real gemstone?
Yes. Moissanite is a real gemstone, silicon carbide. Natural moissanite is extremely rare, so jewellery moissanite is made in a laboratory, with the same properties.
Is moissanite better than diamond?
It is different. Moissanite costs far less and has more fire; diamond is slightly harder (10 vs 9.25) and has a whiter sparkle. Many people choose moissanite for value and brilliance.
How much is 1 carat moissanite in ratti?
One carat is about 1.1 ratti, using the common conversion of 1 ratti = 0.91 carat. We show ratti for every size.
What size moissanite looks like a 1 carat diamond?
A round moissanite of about 6.5 mm looks like a one-carat diamond.
Does moissanite pass a diamond tester?
Many basic thermal diamond testers read moissanite as diamond. A dedicated moissanite tester can tell the difference.
Can moissanite be worn every day?
Yes. At 9.25 on the Mohs scale it is one of the hardest gemstones and very suitable for daily wear.
Carat and ratti figures are approximate averages; moissanite is chosen by millimetre size.
Ready to choose your moissanite?
Every shape has a full size chart in millimetres, carats and ratti, with a true-to-size view on your own screen.
Shop moissanite
