Can Moissanite Get Scratched? Understanding the Mohs Hardness Scale

It's one of the first questions people ask when they're considering moissanite for an engagement ring or everyday jewelry: can it scratch? The concern is understandable. A scratched gemstone is a damaged gemstone — one that has lost some of the surface clarity and brilliance that made it beautiful in the first place. And for a piece of jewelry you intend to wear every day for the rest of your life, the question of scratch resistance is not a minor one.

The short answer is: moissanite is extremely difficult to scratch under normal daily wear conditions. The longer answer involves understanding what hardness actually means, what the Mohs scale measures, and what specific materials in your daily environment are capable of scratching a gemstone rated 9.25. This guide gives you both answers — the short one and the complete one.

What Is the Mohs Hardness Scale?

The Mohs hardness scale was developed in 1812 by German mineralogist Friedrich Mohs as a way to rank minerals by their resistance to scratching. The scale runs from 1 (talc, the softest mineral — scratched by a fingernail) to 10 (diamond, the hardest natural substance on earth — scratched only by other diamonds).

The key principle of the Mohs scale is simple: a harder mineral will scratch a softer one, and a softer mineral cannot scratch a harder one. If you drag a piece of quartz (Mohs 7) across a piece of feldspar (Mohs 6), the quartz will scratch the feldspar. If you drag the feldspar across the quartz, nothing happens. This directional relationship is what makes the scale useful for predicting real-world scratch resistance.

It's important to understand that the Mohs scale is not linear. The difference in hardness between a 9 and a 10 is far greater than the difference between a 1 and a 2. Diamond (10) is approximately four times harder than corundum (9, the mineral family of ruby and sapphire) in absolute terms, even though they're only one step apart on the scale.

Where Does Moissanite Fall on the Mohs Scale?

Moissanite scores 9.25 on the Mohs hardness scale — the second hardest gemstone used in fine jewelry, behind only diamond (10). This places moissanite above ruby and sapphire (9), significantly above emerald (7.5–8), morganite (7.5–8), and white topaz (8), and dramatically above softer gemstones like opal (5.5–6.5) and pearl (2.5–4.5).

The practical significance of this rating is that moissanite can only be scratched by materials that are harder than 9.25 on the Mohs scale. In the natural world, the only common material harder than moissanite is diamond. In the manufactured world, certain industrial abrasives (silicon carbide, boron carbide, cubic boron nitride) are harder, but these are not materials you encounter in daily life.

What Can Scratch Moissanite?

Diamond

Diamond, at Mohs 10, is the only gemstone that can scratch moissanite. In practice, this means that if you store a moissanite ring in the same compartment as a diamond ring and they rub against each other repeatedly, the diamond could theoretically scratch the moissanite. This is why we recommend storing jewelry pieces separately — not because moissanite is fragile, but because any gemstone can be scratched by a harder one, and proper storage is good practice for all fine jewelry.

Other Moissanite

Two moissanite stones of equal hardness can scratch each other if they're in sustained, direct contact. Again, this is a storage concern rather than a wear concern — moissanite stones don't come into contact with each other during normal wear.

Industrial Abrasives

Certain industrial abrasives — silicon carbide grinding wheels, boron carbide compounds, cubic boron nitride tools — are harder than moissanite and could scratch it. These are not materials encountered in daily life or in any normal jewelry-wearing context.

What Cannot Scratch Moissanite?

The list of materials that cannot scratch moissanite is essentially everything you encounter in daily life:

• Sand and dust: Composed primarily of quartz (Mohs 7) — significantly softer than moissanite. Sand is one of the most common sources of gemstone scratching for softer stones; it cannot scratch moissanite.
• Metal surfaces: Steel (Mohs 4–4.5), stainless steel (Mohs 5.5–6.5), and most other metals are far softer than moissanite. Countertops, gym equipment, steering wheels, and tools will not scratch moissanite.
• Ceramic and porcelain: Mohs 6–7 — softer than moissanite.
• Glass: Mohs 5.5 — significantly softer than moissanite. Moissanite will scratch glass, not the other way around.
• Most gemstones: Ruby and sapphire (Mohs 9) are slightly softer than moissanite. Emerald, morganite, topaz, and most other gemstones are significantly softer.
• Your fingernails: Mohs 2.5 — far softer than moissanite.
• Cosmetics and cleaning products: These are chemical substances, not abrasives, and they interact with gemstones through chemical rather than mechanical means. Moissanite's chemical stability means it is unaffected by virtually all cosmetics and cleaning products.

Hardness vs. Toughness: An Important Distinction

Hardness (resistance to scratching) and toughness (resistance to chipping and breaking from impact) are different properties, and it's important not to confuse them. A gemstone can be very hard but relatively brittle — diamond is the classic example. Despite being the hardest natural substance, diamond can chip or cleave along its crystal planes if struck at the right angle with sufficient force.

Moissanite has both excellent hardness (9.25) and excellent toughness. It has no cleavage planes — no structural weaknesses along which it can split — and it is highly resistant to chipping from impact. This combination of hardness and toughness makes moissanite one of the most durable gemstones available for fine jewelry, and one of the best choices for rings and bracelets that are subject to daily physical impact.

What About the Metal Setting?

It's worth noting that while the moissanite stone itself is extremely scratch-resistant, the metal setting is a different matter. Gold, silver, and platinum are all significantly softer than moissanite and will show wear over time — particularly in high-contact areas like the underside of a ring band. This is normal and expected for any fine jewelry worn daily, and it's why we offer our Lifetime Upgrade Program — allowing you to refresh or upgrade your setting at any point while the stone remains as brilliant as the day you bought it.

For plated settings specifically, the plating layer will wear through over time with daily wear, revealing the base metal beneath. This is a function of the plating thickness and wear patterns, not a defect. Re-plating is a routine and inexpensive service that any jeweler can perform.

Practical Scratch Prevention Tips

While moissanite is extremely scratch-resistant, a few simple habits will ensure your stone and setting stay in optimal condition:

• Store jewelry separately: Keep moissanite pieces in individual pouches or compartments to prevent contact with other jewelry, particularly diamond pieces.
• Remove before activities with heavy abrasion: Gardening, masonry work, and similar activities involve sustained contact with hard, abrasive materials. Removing your ring for these activities protects the setting more than the stone.
• Clean regularly: Surface buildup of oils and residue can make a stone appear dull, even without scratching. A monthly cleaning with warm water and a soft brush keeps the surface clear and the brilliance at its peak. For a complete care guide, see our article on keeping your moissanite crystal clear.
• Have the setting checked annually: Prongs can loosen over time with daily wear. An annual check by a jeweler ensures the stone is secure and the setting is in good condition.

The Bottom Line

Moissanite at Mohs 9.25 is one of the most scratch-resistant gemstones available for fine jewelry. Under normal daily wear conditions — which include everything from gym workouts to cooking to gardening to travel — moissanite will not scratch. The only material that can scratch it in a jewelry context is diamond, and proper storage eliminates even that risk.

If scratch resistance is a priority for you — and for anyone considering an engagement ring or everyday jewelry, it should be — moissanite is one of the best choices available. It is, in this respect as in most others, a gemstone designed for real life.

Explore our full collection of moissanite rings and bracelets, all backed by our Lifetime Gemstone Warranty. For more on moissanite's everyday durability, see our complete guide on moissanite for everyday wear.