( Revelation 4:3 , RSV, "sardius;" Heb. 'odhem; LXX., Gr. sardion, from a root meaning "red"), a gem of a blood-red colour. It was called "sardius" because obtained from Sardis in Lydia. It is enumerated among the precious stones in the high priest's breastplate ( Exodus 28:17 ; 39:10 ). It is our red carnelian.

These dictionary topics are from
M.G. Easton M.A., D.D., Illustrated Bible Dictionary, Third Edition,
published by Thomas Nelson, 1897. Public Domain, copy freely.