The Mohs Scale of Hardness including Birthstones

Birthstones come in differing hardness and this is measured using the Mohs Scale of hardness. We have listed each gemstone next to its relevant hardness.

When choosing a gift with a gemstone make sure it will withstand the wear and tear that it is likely to receive. The softer the gemstone the more likely it is to be damaged. This should not stop you buying things like pearls. The person receiving the gift should be aware that the stone may be damaged by perfume and certain body creams. Gold, silver and platinum may also be discolored by creams.

The table below shows the Scale of Hardness. It was designed in 1812 by Frederich Mohs, a German mineralogist. Frederich Mohs selected the ten minerals that were common or more readily available back then. This is an arbitrary scale, with very irregular intervals.

Hardness	Damaged by
1. Talc	crushable with finger nails
2. Gypsum	can be scored with finger nail
3. Calcite, Pearl	scored with iron nail
4. Fluorite	scored with glass
5. Apatite	scored with a penknife
6. Orthoclase feldspar, Opal	scored with quartz
6.5 Peridot	scored with a file or special steel
7. Quartz, Amethyst, Garnet	scored with a file or special steel
7.5 Aquamarine, Emerald	only scored by corundum or diamonds
8. Topaz	only scored by corundum or diamonds
9. Corundum, Ruby or Sapphire	only scored by a diamond
10. Diamond	only scored by another diamond