Exodus 28:9, 17-21

You shall take two onyx stones and engrave on them the names of the [twelve] sons of Israel

You shall mount on it four rows of stones: the first row shall be a row of ruby, topaz, and emerald; the second row a turquoise, a sapphire, and a diamond; the third row a jacinth, an agate, and an amethyst; and the fourth row a beryl and an onyx and a jasper; they shall be set in gold filigree. The [engraved] stones shall be twelve, according to the names of [the twelve tribes of] the sons of Israel; they shall be like the engravings of a signet, each with its name for the twelve tribes.