Mohs Hardness Scale: Which Gemstones Are Safe for Everyday Wear

The Mohs scale ranks minerals 1 (talc) to 10 (diamond) by scratch resistance — each number can scratch anything below it and be scratched by anything above it. It's a genuinely useful buying filter, but it's not the whole durability picture.

The scale, gemstone by gemstone

• 10 — Diamond. The hardest natural material; nothing but another diamond scratches it.
• 9 — Corundum (ruby, sapphire). Second-hardest natural gem material; excellent for daily wear.
• 8.5 — Chrysoberyl (including alexandrite and cat's-eye).
• 8 — Topaz, spinel.
• 7.5–8 — Beryl (emerald, aquamarine, morganite).
• 7–7.5 — Tourmaline, garnet, zircon.
• 7 — Quartz (amethyst, citrine, quartz varieties).
• 6–7 — Peridot, tanzanite.
• 6–6.5 — Moonstone, feldspar.
• 5–6.5 — Opal, turquoise.
• 2.5–4 — Pearl, coral.

Hardness isn't the same as toughness

A stone can be hard (scratch-resistant) and still brittle (prone to chipping or cleaving along a plane under a sharp knock) — hardness and toughness are different physical properties. Emerald is a good example: at 7.5–8 Mohs it resists scratching reasonably well, but its typically heavy inclusion pattern and fracture-filling (see our treatments guide) make it genuinely more prone to chipping than its hardness number alone would suggest. Tanzanite and opal are both true daily-wear risks for the same reason — softer and more brittle than their Mohs number implies in isolation.

What "safe for daily wear" actually means for a ring

A ring is worn on the hand, which is in constant low-level contact with hard surfaces (door handles, countertops, other jewellery). As a rough guide: 8+ Mohs (diamond, sapphire, ruby, alexandrite, spinel, topaz) is genuinely safe for daily wear in a ring setting. 6.5–8 (tourmaline, garnet, aquamarine, morganite) is fine with reasonably careful wear, but better suited to a protective setting (bezel or half-bezel) than exposed prongs. Below 6.5 (opal, tanzanite, pearl, turquoise, moonstone) is best reserved for earrings, pendants, and occasional-wear rings rather than an everyday piece — or set in a protective bezel if it must be a ring worn daily.

Setting choice matters as much as the stone

A protective bezel or halo setting meaningfully extends the practical wearability of a softer stone by shielding its edges from direct impact — this is why antique jewellers so often bezel-set softer material. If you're set on a lower-hardness stone for a ring you'll wear daily, ask your jeweller about setting style before you ask about the stone.

Related reading

• Non-diamond engagement rings: sapphire, ruby, emerald & moissanite guide
• How gemstones are priced
• Browse the Gemstone Encyclopedia