Amethyst is a form of quartz crystal colored by the FE3+ iron ion which has been exposed to natural radiation, most commonly potassium, creating a purple color within the stone.
Amethyst crystals can vary in hue and color and when heated creates citrine by changing the form of the iron within the stone.
Amethyst is the birthstone for February and jewelry made from amethyst is a very popular gift no matter when recipient was born.
Amethyst is harder than steel and stronger than glass with a Mohs hardness of 7
The ancient Romans and Greeks believed that drinking alcohol from amethyst goblets would prevent them from getting drunk.