Gemstone Hardness Chart
Compare the Mohs hardness, toughness and everyday-wear durability of more than 30 gemstones — and find out at a glance which stones are tough enough for the rings you wear every day.
How the Mohs scale measures gemstone hardness
Hardness is a gem's resistance to being scratched. In 1812 the mineralogist Friedrich Mohs ranked ten reference minerals from talc (1) to diamond (10), where each one scratches everything below it. The scale is relative rather than linear: the jump from corundum (9) to diamond (10) is far bigger than the jump from one number to the next lower down. For jewellery, the practical question is simple — will this stone survive being knocked, rubbed and dropped over years of wear?
Hardness
Resistance to scratches, measured on the Mohs scale. Dust contains quartz (7), so anything softer slowly abrades.
Toughness
Resistance to chipping and breaking. A hard gem can still be brittle — topaz cleaves, emerald fractures, jade barely breaks.
Stability
Resistance to heat, light and chemicals. Opals can crack if they dry out; pearls dislike perfume, sweat and acids.
The scratch test
You can place a stone roughly on the scale with everyday objects. A fingernail registers about 2.5, a copper coin about 3.5, a steel knife or nail about 5.5, and ordinary window glass about 5.5–6. If a stone scratches glass it is harder than 5.5; if a quartz crystal scratches the stone, it is softer than 7. Always test an inconspicuous spot — and never scratch-test a cut gem you value. For an unknown stone, our gemstone identification tool uses a scratch-test hardness bucket alongside colour and lustre to narrow it down.
Why daily-wear durability matters
Rings take more abuse than any other jewellery, so hardness matters most there. The usual guideline is Mohs 7 and above for a ring worn every day, because softer stones lose their polish and pick up scratches from ordinary handling. Softer or more fragile gems are not off-limits — they simply belong in earrings, pendants and brooches, in protective settings, or in rings reserved for special occasions.
Gemstone hardness chart (Mohs scale)
Sort by name or hardness, or filter to the gems hard enough for everyday rings. Each row pairs the Mohs rating with a toughness grade and a one-line wear verdict.
Showing 32 gemstones.
| Category | Toughness | Everyday-wear guidance | ||
|---|---|---|---|---|
| Diamond | 10 | Native carbon | Good | Outstanding for everyday rings; only a sharp blow on a cleavage plane can chip it. |
| Moissanite | 9.25 | Silicon carbide | Excellent | Superb daily durability; second only to diamond in scratch resistance. |
| Sapphire | 9 | Corundum | Excellent | Excellent for daily rings — a top everyday-wear choice after diamond. |
| Ruby | 9 | Corundum | Excellent | Excellent for daily rings — hard and exceptionally tough. |
| Chrysoberyl | 8.5 | Chrysoberyl | Excellent | Excellent for everyday wear; very hard and resistant to knocks. |
| Alexandrite | 8.5 | Chrysoberyl | Excellent | Excellent for daily rings — among the most durable coloured stones. |
| Topaz | 8 | Topaz | Poor | Hard but cleaves easily — fine for occasional wear, protective settings for rings. |
| Spinel | 8 | Spinel | Good | Very good for everyday rings — hard, with no cleavage to worry about. |
| Morganite | 7.5–8 | Beryl | Good | Good for daily wear; durable enough for engagement rings with care. |
| Emerald | 7.5–8 | Beryl | Poor | Hard enough but brittle and included — wear carefully, avoid impacts. |
| Aquamarine | 7.5–8 | Beryl | Good | Good for everyday rings — harder and cleaner than its cousin emerald. |
| Tourmaline | 7–7.5 | Tourmaline | Fair | Okay for everyday rings with a protective setting; avoid hard knocks. |
| Quartz (Rock Crystal) | 7 | Quartz | Good | Good for everyday rings — the 7.0 benchmark for daily-wear hardness. |
| Iolite | 7–7.5 | Cordierite | Fair | Borderline for daily rings — has cleavage, so favour earrings and pendants. |
| Citrine | 7 | Quartz | Good | Good for everyday rings; durable golden quartz that wears well. |
| Amethyst | 7 | Quartz | Good | Good for everyday rings — quartz resists scratching from household dust. |
| Zircon | 6.5–7.5 | Zircon | Fair | Wearable but facet edges abrade — better for pendants and earrings. |
| Tanzanite | 6.5 | Zoisite | Poor | Too soft and brittle for daily rings — best for earrings and pendants. |
| Peridot | 6.5–7 | Olivine | Fair | Wearable but soft enough to abrade — use protective ring settings. |
| Onyx | 6.5–7 | Chalcedony (quartz) | Excellent | Good for everyday wear; tough black chalcedony popular in signet rings. |
| Jade (Jadeite) | 6.5–7 | Jadeite | Excellent | Good for everyday wear — exceptionally tough even though it scratches. |
| Garnet | 6.5–7.5 | Garnet | Good | Good for everyday rings — tough, with no cleavage, though softer than quartz. |
| Agate | 6.5–7 | Chalcedony (quartz) | Excellent | Good for everyday wear — very tough, though softer than crystalline quartz. |
| Moonstone | 6–6.5 | Feldspar | Poor | Soft with cleavage — keep to occasional wear and protective settings. |
| Labradorite | 6–6.5 | Feldspar | Poor | Soft with cleavage; reserve rings for light wear, ideal for pendants. |
| Opal | 5.5–6.5 | Hydrated silica | Poor | Soft, brittle and water-sensitive — wear gently, never in an ultrasonic. |
| Turquoise | 5–6 | Phosphate | Fair | Soft and porous — avoid daily rings; keep away from oils and chemicals. |
| Lapis Lazuli | 5–6 | Rock (lazurite) | Fair | Soft and porous — best in pendants, brooches and earrings, not rings. |
| Malachite | 3.5–4 | Carbonate | Fair | Soft — strictly for pendants, beads and cabochons, never daily rings. |
| Coral | 3–4 | Organic (calcium carbonate) | Fair | Soft organic gem — protect from heat, acids and abrasion. |
| Pearl | 2.5–4.5 | Organic (nacre) | Fair | Very soft — wear as the last thing on, first off; keep from perfume and sweat. |
| Amber | 2–2.5 | Organic (fossil resin) | Poor | Very soft and brittle — for pendants and beads, never rough wear. |
Hardness resists scratches; toughness resists chips and breaks. A hard stone can still be fragile — topaz and emerald are both hard yet cleave or fracture easily.
Gemstone hardness, gem by gem
Diamond hardness
Diamond is a perfect 10 on the Mohs scale — the hardest natural material, and the only gem that can scratch another diamond. That scratch resistance is why it is the default choice for engagement rings meant to last a lifetime. Its one weakness is cleavage: a precise, hard blow on the right plane can chip it, so even a diamond benefits from a secure setting. See the full April birthstone guide to diamond.
Sapphire hardness
Sapphire is Mohs 9 — corundum, second only to diamond and moissanite — and it is also exceptionally tough with no cleavage. That combination makes it one of the best coloured stones for everyday rings, including engagement rings, and it explains why sapphire crystal is used for scratch-proof watch faces. Read more in the September birthstone guide to sapphire.
Ruby hardness
Ruby is the same mineral as sapphire — corundum — so it shares the same Mohs 9 hardness and excellent toughness. Only diamond and moissanite outrank it for scratch resistance, which makes ruby a superb everyday gem that holds its polish for generations. The July birthstone guide to ruby covers colour, value and care.
Emerald hardness
Emerald sits at Mohs 7.5–8, so on hardness alone it is well within everyday-wear range. The catch is toughness: emeralds are brittle and almost always contain fractures and inclusions (the "jardin"), which means they chip far more easily than their hardness suggests. Wear an emerald ring with care, keep it out of ultrasonic cleaners, and prefer protective settings — details are in the May birthstone guide to emerald.
Topaz hardness
Topaz is a hard Mohs 8, but it has perfect basal cleavage, so a sharp knock in the wrong direction can split the stone cleanly. It scratches very little in everyday use yet is best protected in pendants, earrings, or rings with a bezel or low-profile setting. Learn more in our topaz meaning and colours guide.
Amethyst hardness
Amethyst is purple quartz, so it sits right at Mohs 7 with good toughness and no cleavage. That puts it on the everyday-wear threshold: it resists scratches from ordinary dust and wears well in rings, though over many years facet edges may soften slightly. The February birthstone guide to amethyst covers colour grades and care.
Garnet hardness
Garnet spans roughly Mohs 6.5–7.5 depending on the species, and it is reasonably tough with no cleavage. Most red garnets are durable enough for everyday rings, while the softer end of the range is happier in earrings or occasional-wear pieces. See the January birthstone guide to garnet for the different varieties.
Moissanite hardness
Moissanite (silicon carbide) is about Mohs 9.25, harder than any natural gem except diamond, and it is very tough as well. That makes lab-grown moissanite one of the most scratch-resistant and practical diamond alternatives for everyday rings, with even more fire than diamond. Our moissanite vs diamond comparison weighs up the trade-offs.
Tourmaline hardness
Tourmaline ranges from Mohs 7 to 7.5 with only fair toughness, so it scratches little but can chip on hard impact. It works in everyday rings given a protective setting and sensible care, and shines in pendants and earrings where knocks are rarer. The October birthstone guide to tourmaline covers its huge colour range.
Alexandrite hardness
Alexandrite is a variety of chrysoberyl at Mohs 8.5 with excellent toughness, making it one of the most durable coloured gems and an excellent everyday choice — fitting, given how rare and valuable it is. It shares June with the much softer pearl. Read our alexandrite colour-change guide or the June birthstone guide.
Which gems are safe for everyday rings?
For a ring you wear daily, aim for Mohs 7 or higher and good toughness. The safest picks are diamond, moissanite, ruby and sapphire (all 9 or above with excellent toughness), followed by spinel, alexandrite, aquamarine, morganite, garnet and the quartz gems amethyst and citrine. These hold their polish and shrug off the dust and knocks of normal life.
Wear with care if the stone is hard but fragile. Topaz and emerald are hard enough but cleave or fracture, so they want protective settings and gentle handling. Tourmaline, zircon and peridot sit just below the line and do best in bezels or as earrings and pendants.
Save for gentle wear the soft and delicate gems: opal, moonstone, labradorite, tanzanite, turquoise, lapis lazuli, pearl and amber all scratch or chip easily. They are beautiful in pendants, earrings and occasional-wear rings, but not the best choice for a ring on your hand every day. Picking a stone for a specific month? Browse the full birthstone chart or our birthstone jewellery guide.