Dictionary entry

σαρδόνυξ

G. Abbott-Smith's A Manual Greek Lexicon of the New Testament

* σαρδόνυξ (L, σαρδιόνυξ), -υχος, ὁ

(< σάρδιον, ὄνυξ),

sardonyx, a stone marked by the red of the sard and the white of the onyx: Re 21:20.†