Amethyst is a variety of quartz and one of the most important gemstones that has been used since ancient times as a gem.
The very prominent violet blue or purple color of amethyst crystals is so attractive that grabs attention immediately.
Brazil is one of the main suppliers of amethyst, but finest amethysts with excellent and very rich violet blue color are often from mines in Uruguay.
Amethyst is often in form of crystal clusters, specially in geodes (just like quartz). Amethyst geodes are valuable items and some collectors spend a fortune on some giant amethyst geodes of excellent quality.
Amethyst's luster is vitreous (glass like) and its hardness on Mohs scale is 7.