beryl (n.) Look up beryl at Dictionary.com
hard, lustrous mineral, c.1300, from Old French beryl (12c., Modern French béryl), from Latin beryllus, from Greek beryllos, perhaps from Prakrit veruliya, from Sanskrit vaidurya-, of Dravidian origin, perhaps from the city of Velur (modern Belur) in southern India.

Medieval Latin berillus also was applied to any precious stone of a pale green color, to fine crystal, and to eyeglasses (the first spectacle lenses may have been made of beryl), hence German Brille "spectacles," from Middle High German berille "beryl," and French besicles (plural) "spectacles," altered 14c. from Old French bericle.