Sardonyx. 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.
More than 4,500 subjects and proper names are defined and analyzed with corresponding Scripture references. Bible students have used "Smith's Bible Dictionary" since its introduction in the 1880s, making it a trustworthy classic.Wikipedia
Read More