Amethyst, the birthstone for February

Colours
Amethyst is the most valuable form of quartz and is found in various shades of purple, ranging form pale lilac to a deep purple. It can posses a reddish and milky purple quality in its shade.

Physical Properties
Measuring 7 on the Moh’s scale, Amethyst is a fairly hard stone. Amethyst can vary in transparency, ranging from transparent to translucent, all the time though retaining a glassy lustre. An amethyst like other forms of quartz are piezoelectric meaning it is useful in many forms of electronics. The only other gemstone that posses these properties is Tourmaline