Beryl (beryllium aluminum silicate) is one of the most important gem minerals. Beryl is colorless in pure form; it is the many different impurities that give beryl its varied coloration. The most famous beryl is emerald, but other beryl varieties include aquamarine, heliodor and morganite. The name beryl is used for the red and golden varieties, which are simply called red beryl and golden beryl. Beryl is quite a hard stone (7.5-8 on the Mohs scale), so it's suitable for all kinds of jewelry.