Mineral Species: Quartz var. Amethyst

Chemical Formula: SiO2

Chemical Name: Silicon Dioxide

Mineral Class: Tectosilicate

Mineral Notes: Amethyst is the purple variety of Quartz and is a popular gemstone. The name comes from the Greek and means "not drunken." This was perhaps due to the belief that the stone would ward off the effects of alcohol, but more likely the Greeks were referring to the wine-like colour of some specimens they saw. Although it must always be purple to be Amethyst, the mienral can and does have a wide range of purple shades. The colour is caused by the presence of iron.

Description: An unusual specimen consisiting of a "sandwich" of Amethyst crystals. Rather than having a distinct boundary, the crystals overlap along the centre line. Most have good pyramidal form, the colour being lightest at the outer boundaries of the specimen and darkest down the middle. On the tiop surface is a thin layer of pale-green Quartz, resembling the surface of a sponge.

Location: Hawks Tor China Clay Pit, Wadebridge, Cornwall, England.