Amethyst
Amethyst – a mineral, transparent variety of silicon dioxide (SiO2) with purple hue. Its name derives from Greek and means “sober” (a – not, methystos – drunk); ancient Greeks believed that drinking wine from amethyst cups protected the drinker from intoxication.
In Middle Ages amethysts because of their mythical powers were used as amulets protecting mighty knights. They were kept in boxes padded with swallow’s feathers. They warded against not only drinking, but also from a curse, hailstones and locust. They protected soldiers from wounds and betrayal and guided the sailors safely home. Ground amethyst powder was used as a medicine.