Agate

Agate is formed in cocentric layers that lends itself to a multi-coloured striped appearance. This ensures that no two agates are quite the same. It is often used in cameos and other fashion jewellery. Agate also is what forms the basis of petrified wood.

Agate
Colour Description
Multi-coloured in cocentric layers Micro-crystalline quartz (chalcedony). Mohs hardness rating of 6.5 – 7.0.