Exodus 28:15-29 and 39:9-21
"Fashion a breastpiece for making decisions--the work of skilled hands. Make it like the ephod: of gold, and of blue, purple and scarlet yarn, and of finely twisted linen. It is to be square - a span long and a span wide - and folded double. Then mount four rows of precious stones on it.
The first row shall be carnelian, chrysolite and beryl;
the second row shall be turquoise, lapis lazuli and emerald;
the third row shall be jacinth, agate and amethyst;
the fourth row shall be topaz, onyx and jasper.
Mount them in gold filigree settings. There are to be twelve stones, one for each of the names of the sons of Israel, each engraved like a seal with the name of one of the twelve tribes. "For the breastpiece make braided chains of pure gold, like a rope. Make two gold rings for it and fasten them to two corners of the breastpiece. Fasten the two gold chains to the rings at the corners of the breastpiece, and the other ends of the chains to the two settings, attaching them to the shoulder pieces of the ephod at the front. Make two gold rings and attach them to the other two corners of the breastpiece on the inside edge next to the ephod. Make two more gold rings and attach them to the bottom of the shoulder pieces on the front of the ephod, close to the seam just above the waistband of the ephod. The rings of the breastpiece are to be tied to the rings of the ephod with blue cord, connecting it to the waistband, so that the breastpiece will not swing out from the ephod. "Whenever Aaron enters the Holy Place, he will bear the names of the sons of Israel over his heart on the breastpiece of decision as a continuing memorial before the LORD. They fashioned the breastpiece -the work of a skilled craftsman. They made it like the ephod: of gold, and of blue, purple and scarlet yarn, and of finely twisted linen.
It was square - a span long and a span wide - and folded double. Then they mounted four rows of precious stones on it.
The first row was carnelian, chrysolite and beryl;
the second row was turquoise, lapis lazuli and emerald;
the third row was jacinth, agate and amethyst;
the fourth row was topaz, onyx and jasper.
They were mounted in gold filigree settings. There were twelve stones, one for each of the names of the sons of Israel, each engraved like a seal with the name of one of the twelve tribes. For the breastpiece they made braided chains of pure gold, like a rope. They made two gold filigree settings and two gold rings, and fastened the rings to two of the corners of the breastpiece. They fastened the two gold chains to the rings at the corners of the breastpiece, and the other ends of the chains to the two settings, attaching them to the shoulder pieces of the ephod at the front. They made two gold rings and attached them to the other two corners of the breastpiece on the inside edge next to the ephod. Then they made two more gold rings and attached them to the bottom of the shoulder pieces on the front of the ephod, close to the seam just above the waistband of the ephod. They tied the rings of the breastpiece to the rings of the ephod with blue cord, connecting it to the waistband so that the breastpiece would not swing out from the ephod - as the LORD commanded Moses.