ETYM French béryl, Old Fren. beril, Latin beryllus, Greek beryllos, prob. from Skr. vaidűrya. Related to Brilliant.
The chief source of beryllium; colored transparent varieties are valued as gems.
Mineral, beryllium aluminum silicate, Be3Al2Si6O18, which forms crystals chiefly in granite. It is the chief ore of beryllium. Two of its gem forms are aquamarine (light-blue crystals) and emerald (dark-green crystals).
Well-formed crystals of up to 200 tons have been found.