Amethyst, a variety of semiprecious quartz that is colored violet-blue or purple by manganese. Amethyst is often used in jewelry. Amethyst crystals are found in mineral veins and in cavities that occur in agate and certain rocks. The finest amethysts are found in Uruguay, Brazil, and Siberia. Beautiful amethysts are obtained along the shores of Lake Superior. Amethysts are also found in Arizona. The amethystine sapphire, a gem of great beauty and brilliance, is often called oriental amethyst. It is a violet or purple sapphire, and much more valuable than amethyst.

The amethyst is the birthstone for February and symbolizes sincerity.