Coralium, coralij, Lapis est rubri coloris. Plin. Corall, which in the sea groweth lyke a shrubbe or bushe, and taken out wareth harde as a stone: while it is in the water it is of colour greenish and couered with mosse, when it is dressed it is redde and smooth.
Lewis and Short: Latin dictionary
cōrālĭum or cūrālĭum (cŏral-lum, Sid. Carm. 11, 110), ii, n., = kora/llion; Ion. koura/lion, coral, esp. red coral, Plin. 32, 2, 11, 21 sq.: curalium, id. 32, 2, 11, 21 and 22: coralium, Ov. M. 4, 750; 15, 416; plur.: coralia, Claud. Nupt. Hon. et Mar. 169.—In the form corallius, i, f., Plin. 37, 10, 56, 153; masc., Isid. Orig. 16, 8, 1.