Gemstones and the Mohs Hardness Scale

This scale of 1 to 10 was created in 1812 by Friedrich Mohs for the identification of minerals. He selected 10 minerals that varied in hardness and placed them on a scale from 1 to 10, using talc as the softest, scoring 1 and diamond as the hardest, scoring 10. Other minerals were scaled in between this depending on their resistance to being scratched after a certain amount of pressure was applied.

This scale has continued to be in use by geologists and can be a handy guide to determine the durability of gemstone minerals.

In terms of jewellery, this knowledge is useful for understanding the durability of your gemstones and impacts whether it is suitable for daily wear. For softer gemstones (lower on the Mohs scale), take care to store in soft packaging away from other jewellery, to avoid scratching and only clean with lukewarm water with a mild soap.

I've attached a list below of gemstones and where they are on the Mohs scale.

Abalone	3.5
Agate	6.5 – 7
Amazonite	6 – 6.5
Amber	2 – 2.5
Amethyst	7
Ametrine	7
Ammonite	4
Angelite	3.5
Apatite	5
Aquamarine	7.5 – 8
Arfvedsonite	5.5 – 6
Aventurine	7
Azurite	3.5 – 4
Bloodstone	6.5 – 7
Bronzite	5 – 6
Calcite	3
Carnelian	6.5 – 7
Charoite	5
Chrysocolla	2 – 4
Citrine	7
Coral	3 – 4
Diamond	10
Diopside	5 – 6
Emerald	7.5 – 8
Eudialyte	5 – 5.5
Fluorite	4
Fuchsite	2 – 3
Garnet	6.5 – 7.5
Grandidierite	7 – 7.5
Hematite	5.5 – 6.5
Howlite	3 – 3.5
Hypersthene	5 – 6
Iolite	7 – 7.5
Jade / Jadeite	6.5 – 7
Jasper	6.5 – 7
Jet	2.5 - 4
Kunzite	6.5 – 7
Kyanite	4 – 4.5
Labradorite	6 – 6.5
Lapis Lazuli	5 – 6
Larimar	4.5 – 5
Larvakite	6 – 6.5
Lepidolite	2.5 – 3
Magnesite	3.5 – 4.5
Malachite	3.5 – 4
Merlinite	7
Moldavite	5.5
Mookite	6.5 – 7
Moonstone	6 – 6.5
Morganite	7.5 – 8
Mother of Pearl	2.5 – 4.5
Nephrite Jade	6 – 6.5
Nilamani	9
Obsidian	5 – 6
Onyx	6.5 – 7
Opal	5.5 – 6.5
Pearl	2.5 – 4.5
Peridot	6.5 – 7
Petrified Wood	7
Pietersite	6.5 – 7
Prehnite	6 - 6.5
Purpurite	4 – 4.5
Pyrite	6 – 6.5
Quartz	7
Rhodocrosite	4
Rhodonite	5.5 – 6.5
Rose Quartz	7
Ruby	9
Sapphire	9
Scolecite	5 – 5.5
Selenite	2 – 3
Septarian	3.5 – 4
Serpentine	2.5 – 5.5
Shattuckite	3.5 – 4
Shungite	3.5 – 4
Sodalite	5.5 – 6
Spinel	8
Sugilite	6 – 6.5
Sunstone	6 – 6.5
Tanzanite	6.5 – 7
Tektite	6 – 7
Thulite	6 – 6.5
Tigers Eye	7
Topaz	8
Tourmaline	7 – 7.5
Turquoise	5 – 6
Unakite	6 – 7
Zoisite	6.5 – 7