What Is the Mohs Hardness Scale?
The Mohs Hardness Scale is a relative measure of a mineral's resistance to scratching, developed by German mineralogist Friedrich Mohs in 1812. It ranks minerals from 1 (softest) to 10 (hardest), with each level able to scratch all minerals below it. It remains one of the most practical tools in gemology for understanding how a stone will hold up to everyday wear.
The Scale at a Glance
- 1 – Talc: The softest mineral. Easily scratched by a fingernail.
- 2 – Gypsum / Selenite: Can be scratched by a fingernail. Selenite wands and plates are beautiful but extremely delicate.
- 3 – Calcite: Scratched by a copper coin. Includes many banded agates and some calcite specimens.
- 4 – Fluorite: Scratched by a steel knife. Stunning colors but requires careful handling.
- 5 – Apatite: Scratched by a steel file. Some turquoise falls in this range.
- 6 – Feldspar / Labradorite / Moonstone: Can scratch glass. Suitable for pendants and earrings; use caution in rings and bracelets.
- 7 – Quartz (Amethyst, Citrine, Rose Quartz, Clear Quartz): Highly durable. Excellent for all jewelry types.
- 8 – Topaz / Spinel: Very hard. Resistant to most everyday scratching.
- 9 – Corundum (Sapphire, Ruby): Extremely hard. Ideal for high-wear jewelry.
- 10 – Diamond: The hardest natural material. Scratches everything below it.
What This Means for Your Jewelry
Understanding hardness helps you make smarter decisions about how you wear and store your pieces:
- Rings & Bracelets experience the most contact and abrasion. Stick to stones rated 7 or above (quartz family and harder) for everyday wear.
- Pendants & Earrings are lower-impact. Softer stones like moonstone (6), labradorite (6–6.5), and even fluorite (4) can work beautifully here.
- Storage: Never store gemstones loose together — harder stones will scratch softer ones. Use individual pouches or compartmentalized boxes.
- Cleaning: Avoid ultrasonic cleaners for stones below 7, and never use harsh chemicals on organic gems like pearl or amber.
- Water exposure: Some stones (selenite, pyrite, malachite) are damaged by prolonged water contact regardless of hardness. Always check care instructions specific to your stone.
Our Jewelry & Hardness
At Brie & Marie, we include care guidance with every piece we sell. If you're ever unsure about how to care for a specific stone in your collection, reach out — we're happy to help you keep your pieces beautiful for years to come.
