Rich Purple Amethyst Crystals

Three beautiful amethyst stones from South Africa.  Each piece boasts rich purple colour but some colour zoning can also be seen.

Colour zoning which is quite common in amethyst means there's a variation in colour within the crystal.

The difference in colour can often be so subtle it's hardly noticeable.  The most extreme example of colour zoning is chevron amethyst.

The ancient Greek philosopher Theophrastus wrote about amethyst and noted it changed colour when exposed to fire.  Heating a mineral alters its chemical composition which can bring about a change in colour.

A significant amount of commercial grade citrine is heated amethyst.  Most of the world's finest rubies and sapphires are heated to enhance or change their colour.