Bible Dictionaries
Sardonyx

Watson's Biblical & Theological Dictionary

σαρδονυξ , Revelation 21:20 . A precious stone which seems to have its name from its resemblance partly to the sardius and partly to the onyx. It is generally tinged with black and blood colour, which are distinguished from each other by circles or rows, so distinct that they appear to be the effect of art.

Bibliography Information
Watson, Richard. Entry for 'Sardonyx'. Richard Watson's Biblical & Theological Dictionary. https://www.studylight.org/​dictionaries/​eng/​wtd/​s/sardonyx.html. 1831-2.