Is it ensure, insure, or assure?
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.
A usually green or bluish-green hexagonal mineral occurring as transparent to translucent prisms in igneous and metamorphic rocks. Transparent varieties, such as emeralds and aquamarine, are valued as gems. Beryl is the main source of the element beryllium. Chemical formula: Be3Al2Si6O18.
the rendering in the Authorized Version of the Hebrew word _tarshish_, a precious stone; probably so called as being brought from Tarshish. It was one of the stones on the breastplate of the high priest (Ex. 28:20; R.V. marg., "chalcedony;" 39:13). The colour of the wheels in Ezekiel's vision was as the colour of a beryl stone (1:16; 10:9; R.V., "stone of Tarshish"). It is mentioned in Cant. 5:14; Dan. 10:6; Rev. 21:20. In Ezek. 28:13 the LXX. render the word by "chrysolite," which the Jewish historian Josephus regards as its proper translation. This also is the rendering given in the Authorized Version in the margin. That was a gold-coloured gem, the topaz of ancient authors.