The first question most people ask before buying moissanite is simple: will it scratch? Short answer: almost nothing you meet in daily life can scratch it. Here's what moissanite hardness means, how it compares to other stones, and what it does and doesn't protect against.
How hard is moissanite?
Moissanite scores 9.25 on the Mohs hardness scale. Diamond is 10. The Mohs scale measures scratch resistance: a harder material scratches a softer one, never the reverse.
| Material | Mohs hardness |
|---|---|
| Diamond | 10 |
| Moissanite | 9.25 |
| Sapphire and ruby | 9 |
| Cubic zirconia | 8 to 8.5 |
| Quartz (found in dust and sand) | 7 |
| Glass | 5.5 |
The quartz line matters most. Household dust contains tiny quartz particles at 7 on the scale. Over time, they dull softer stones like cubic zirconia and glass. Moissanite sits well above that line, which is why it keeps its polish for life.
Hardness vs toughness: the part people forget
Hardness is about scratches. Toughness is about how a stone handles a hard knock. Moissanite does well on both, and it's tougher than many other gemstones. Still, any stone can chip if it hits a hard edge at the wrong angle, like a granite countertop or a car door.
The setting is usually the weak point, not the stone. Prongs can bend with years of wear. Have rings you wear every day checked once a year, especially engagement rings and wedding bands.
Is moissanite good for everyday wear?
Yes. It's one of the best choices for jewelry you never take off. That's why it works so well for pieces that see constant contact:
- Rings, which hit tables, keys and steering wheels all day
- Tennis bracelets, which rub against desks and laptops
- Stud and hoop earrings, which you can sleep in
Moissanite heat resistance
Moissanite also handles heat better than most gems. It won't be damaged by a jeweler's torch during repairs, and it won't change color from sun exposure. The metal around it is more sensitive, so the usual care rules still apply. See our jewelry care guide.
How to protect your moissanite
- Take rings off for the gym, gardening and heavy cleaning.
- Store pieces separately so stones don't rub against each other or against softer metal.
- Clean them every week or two. Here's how to clean moissanite safely.
Quick answers
Can moissanite scratch? Almost nothing but diamond can scratch it. Keys, sand, dust and glass can't.
Can moissanite break? It's very hard to break, but a sharp blow at the wrong angle can chip any gemstone, including diamond.
Is moissanite harder than sapphire? Yes, slightly: 9.25 against 9.
Curious how that hardness translates into sparkle? Read moissanite vs diamond sparkle, or browse our moissanite rings.
