The Collaborative International Dictionary of English v.0.48:

Beryl \Ber"yl\ (b[e^]r"[i^]l), n. [F. b['e]ryl, OF. beril, L.
   beryllus, Gr. bh`ryllos, prob. fr. Skr. vai[dsdot][=u]rya.
   Cf. Brilliant.] (Min.)
   A mineral of great hardness, and, when transparent, of much
   beauty. It occurs in hexagonal prisms, commonly of a green or
   bluish green color, but also yellow, pink, and white. It is a
   silicate of aluminum and beryllium. The aquamarine is a
   transparent, sea-green variety used as a gem. The emerald
   is another variety highly prized in jewelry, and
   distinguished by its deep color, which is probably due to the
   presence of a little oxide of chromium.
   [1913 Webster]

WordNet (r) 3.0 (2006):

beryl
    n 1: the chief source of beryllium; colored transparent
         varieties are valued as gems

Easton's 1897 Bible Dictionary:

Beryl
   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.