Exodus 28:8

They shall use the gold, and the blue, and the purple, and the scarlet, and the fine linen.

“They shall make the ephod of gold, blue, purple, scarlet, and fine twined linen, the work of the skillful workman.

It shall have two shoulder straps joined to the two ends of it, that it may be joined together.

You shall take two onyx stones, and engrave on them the names of the children of Israel.

Six of their names on the one stone, and the names of the six that remain on the other stone, in the order of their birth.

With the work of an engraver in stone, like the engravings of a signet, you shall engrave the two stones, according to the names of the children of Israel. You shall make them to be enclosed in settings of gold.