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Sardonyx
Sardonyx [EBD]
(Rev. 21:20), a species of the carnelian combining the sard and the onyx, having three layers of opaque spots or stripes on a transparent red basis. Like the sardine, it is a variety of the chalcedony.
Sardonyx [NAVE]
SARDONYX, a precious stone.Figurative
In the foundation of the heavenly city, Rev. 21:20.
SARDONYX [SMITH]
a name compounded of sard and onyx , two precious stones, varieties of chalcedony or agate. The sardonyx combines the qualities of both, whence its name. It is mentioned only in (Revelation 21:20) The sardonyx consists of "a white opaque layer, superimposed upon a red transparent stratum of the true red sard." It is, like the sard, merely a variety of agate, and is frequently employed by engravers for signet-rings.Also see definition of "Sardonyx" in Word Study