
The Moh’s hardness scale refers to scratch hardness. The resistance of one mineral to be scratched by another.
Friedrich Mohs (1773-1839), a Viennese mineralogist, introduced the term scratch hardness. The scale ranges from the softest at 1 through to the hardest at 10. Gemstones with a hardness of 1 and 2 are considered to be soft, from 3 to 5 medium, with 6 and over considered to be hard.
Because dust can contain quartz, it is important to realise that household dust can damage the lustre and brilliance of gemstones with a hardness below 7. Jewellery set with these stones should be well cared for to maintain their continued brilliance.
This table of Moh’s hardness lists gemstones by name alphabetically.
A B C – D E F G H – I J K L M N O P – Q R S T U V W X Y Z
Gemstone | Hardness |
---|---|
Aegirine | 6 |
Alexandrite | 8 ½ |
Almandine | 7-7 ½ |
Amazonite | 6-6 ½ |
Amblygonite | 6 |
Amethyst | 7 |
Andalusite | 7½ |
Andesine | 6-6 ½ |
Anorthoclase | 6-6 ½ |
Aquamarine | 7½-8 |
Aventurine | 7 |
Axinite | 6 ½ -7 |
Benitoite | 6-6 ½ |
Bytownite | 6-6 ½ |
Bixbyite | 6-6 ½ |
Boracite | 7-7 ½ |
Cassiterite | 6-7 |
Chalcedony | 6 ½ -7 |
Chambersite | 7 |
Chondroite | 6-6 ½ |
Chromdravite | 7 |
Chrysoberyl | 8½ |
Chrysoprase | 6 ½ -7 |
Citrine | 7 |
Clinohumite | 6 |
Clinozoisite | 6-7 |
Cordierite | 7-7 ½ |
Covellite | 1½ -2 |