What is the Mohs Scale of Hardness?
Mohs Scale of Hardness is used to measure how resistant a gemstone is to scratching. In jewellery, this helps determine how suitable a gemstone is for everyday wear, particularly for rings that are exposed to regular contact and impact.
The scale runs from 1 to 10, with 10 being the hardest.
Mohs Scale of Hardness for Gemstones
Below is a practical guide showing where commonly used gemstones sit on the Mohs Scale.
1 – Very Soft Gemstones
Talc
Extremely soft and not used in fine jewellery.
2 – Soft Gemstones
Gypsum
Selenite
Rarely used in jewellery due to poor durability.
3 – Soft Gemstones
Calcite
Amber
Pearl
Coral
Typically used in occasional wear or protected settings.
4 – Moderately Soft Gemstones
Fluorite
Obsidian
Not recommended for everyday jewellery.
5 – Moderate Hardness Gemstones
Apatite
Turquoise
Opal
These gemstones require careful wear and protective settings.
6 – Fairly Durable Gemstones
Tanzanite
Peridot
Feldspar group gemstones, including:
- Moonstone
- Labradorite
- Sunstone
Suitable for jewellery with mindful wear.
7 – Durable Gemstones
Tourmaline
Tsavorite
Garnets, such as:
- Pyrope
- Spessartite
Quartz group gemstones, including:
- Amethyst
- Citrine
- Smoky Quartz
- Rose Quartz
- Onyx
Durable enough for regular wear with proper care.
8 – Very Durable Gemstones
Emerald
Topaz
Spinel
Aquamarine
Morganite
Alexandrite
Well suited to everyday jewellery.
9 – Extremely Durable Gemstones
Ruby
Sapphire
Excellent for daily wear, including engagement rings.
10 – Diamond
Diamond
The hardest natural gemstone, offering exceptional scratch resistance.
Why This Matters
As a general guide, gemstones rated 7 and above are considered suitable for everyday jewellery. Softer gemstones can still be worn and enjoyed, but they benefit from thoughtful design, protective settings, and a little extra care.
It’s also worth noting that hardness is only one aspect of durability. Craftsmanship and skill of setting play an important role in how a gemstone performs over time. Our expert artisans take the utmost care when setting all gemstones and diamonds.
In Summary
The Mohs Scale of Hardness is a helpful tool for understanding how gemstones compare in terms of wear and scratch resistance. Knowing where a gemstone sits on the scale allows you to choose stones that suit your lifestyle, while still enjoying the beauty and individuality each gemstone offers.
If you’d like advice on choosing the right gemstone for your jewellery, our team is always happy to help, contact us with your questions.
Rhona x
