Onyx stones
So called from their likeness to the nail of a man's finger: the Targum of Onkelos calls them stones of beryl; and the Targum of Jonathan gems of beryl; and the Septuagint version, stones of sardius; and some take them to be the sardonyx stones, which have a likeness both to the onyx and to the sardius:
and stones to be set in the ephod, and in the breastplate;
two onyx stones were set in the ephod, one of the garments of the high priest, and an onyx stone, with eleven other precious stones, were set in the breastplate of the high priest: these stones were doubtless among the jewels set in gold and silver the Israelites had of the Egyptians, and brought with them out of Egypt.