Exodus 39:5-7

Amplified Bible

⁵ The skillfully woven sash with which to bind it, which was on the ephod [to hold it in place], was like its workmanship, of the same material: of gold and of blue, purple, and scarlet fabric, and fine twisted linen, just as the Lord had commanded Moses.

⁶ They made the onyx stones, set in settings of gold filigree; they were engraved as signets are engraved, with the names of [the twelve tribes of] the sons of Israel. ⁷ And he put them on the shoulder pieces of the ephod to be memorial stones (a remembrance) for the sons of Israel (Jacob), just as the Lord had commanded Moses.