Reference

Mohs Hardness Scale

Every crystal, mineral, and stone mapped to the Mohs scale. See at a glance what scratches what, what survives daily wear, and what needs careful handling.

Display Only

Too soft for jewelry or frequent handling. Display specimens.

Gentle Handling

Pendants and earrings okay. Avoid rings and bracelets.

Moderate Wear

Occasional jewelry fine. Will scratch with daily ring wear.

Durable

Suitable for most jewelry with reasonable care.

Very Durable

Excellent for all jewelry types including daily-wear rings.

Mohs Reference: Diamond·Scratches everything

Diamond

Mohs Reference: Corundum·Ruby and sapphire

Ruby Sapphire

8.5

Mohs Reference: Corundum·Ruby and sapphire

Alexandrite Cat's Eye Chrysoberyl

Mohs Reference: Topaz

Spinel Topaz

7.5

Mohs Reference: Topaz

Aquamarine Emerald Morganite Rhodolite Garnet Tourmaline Zircon

6.5

Mohs Reference: Quartz·Scratches steel

Benitoite Jade Kunzite Labradorite Peridot Prehnite Pyrite Sunstone Tanzanite Unakite

Mohs Reference: Orthoclase·Scratches glass (5.5)

Amazonite K2 Stone Libyan Desert Glass Moonstone Nuummite Rhodonite Sugilite Turquoise

5.5

Mohs Reference: Orthoclase·Scratches glass (5.5)

Hematite Lapis Lazuli Magnetite Moldavite Obsidian Opal Pink Opal Scolecite Snowflake Obsidian Sodalite Tiffany Stone

Mohs Reference: Apatite·Steel knife scratches it (5.5)

Apophyllite Bumble Bee Jasper Charoite Dioptase Fluorapatite Hemimorphite Larimar Lava Rock

4.5

Mohs Reference: Apatite·Steel knife scratches it (5.5)

Kyanite Variscite

Mohs Reference: Fluorite

Ammolite Fluorite Septarian

3.5

Mohs Reference: Fluorite

Angelite Aragonite Azurite Cavansite Celestite Cuprite Howlite Malachite Rhodochrosite Serpentine Shungite Sphalerite Stilbite

Mohs Reference: Calcite·Copper coin scratches it (3.5)

Calcite Jet Pearl Vanadinite Wulfenite

2.5

Mohs Reference: Calcite·Copper coin scratches it (3.5)

Amber Bismuth Chrysocolla Crocoite Galena Gold Lepidolite Native Copper Seraphinite Silver

Mohs Reference: Gypsum·Fingernail scratches it (2.5)

Desert Rose Selenite

Practical Scratch Tests

The Mohs scale is relative, not linear. The jump from 9 to 10 (corundum to diamond) represents a far greater hardness difference than the jump from 1 to 9 combined. A mineral at hardness 7 is not seven times harder than hardness 1.

Common test objects

Fingernail: ~2.5

Copper coin: ~3.5

Glass plate: ~5.5

Steel knife: ~5.5

Steel file: ~6.5

Porcelain streak plate: ~7

Key thresholds

Below 3: Scratched by fingernail

Below 5.5: Scratched by a knife

Below 7: Scratched by quartz (sand)

7+: Survives contact with sand and dust

8+: Excellent for all jewelry

Why does hardness 7 matter so much? Because quartz is the most common mineral on Earth, and quartz dust is present in household dust. A stone below hardness 7 will gradually develop micro-scratches from normal exposure. Above 7, it stays polished.