Beryllus, m. & fœm. gen. Plin. A certaine prerious stone called Becrill, in facion sire square, in colour like oyle or water in the sea.
Lewis and Short: Latin dictionary
bēryllus (beryllus, Prud. Psych. 855; bērillus, Isid. Orig. 16, 7, 5; berul-lus, Plin. 37, 5, 20, 76 Jan.), i, m., = bh/rullos. I.A precious stone of a sea-green color, coming from India, beryl, Prop. 4 (5), 7, 9; Plin. 37, 5, 20, 76 sqq.; Isid. Orig. l. l.; Sol. 53; Juv. 5, 37; Dig. 39, 4, 16, 7.—B.Meton. for a ring with a beryl, Prop. 4 (5), 7, 9.—II. Beryllus aëroides, = bh/rullos a)eroeidh/s, the sapphire, Plin. l. l. 77.