The breastplate (Ex 39:8-39:21)

“He made the breastplate in skilled work, like the work of the ephod, of gold, of blue, purple, and crimson yarns, and of fine twisted linen.  It was square.  The breastplate was made double, a span in length and a span in width when doubled.   They set in it four rows of stones.  A row of carnelian, chrysolite, and emerald was the first row.  The second row was turquoise, sapphire, and moonstone.  The third row was a jacinth, an agate, and an amethyst.  The fourth row was a beryl, an onyx, and jasper.  They were enclosed in settings of gold filigree. There were twelve stones with the names corresponding to the names of the sons of Israel.  They were like signets, each engraved with its name, for the twelve tribes.   They made on the breastplate chains of pure gold, twisted like cords.  They made two settings of gold filigree and two gold rings, and put the two rings on the two edges of the breastplate.   They put the two cords of gold in the two rings at the edges of the breastplate.  Two ends of the two cords they had attached to the two settings of filigree.  In this way they attached it in front to the shoulder-pieces of the ephod.  Then they made two rings of gold, and put them at the two ends of the breastplate, on its inside edge next to the ephod.  They made two rings of gold.  They attached them in front to the lower part of the two shoulder-pieces of the ephod, at its joining above the decorated band of the ephod.  They bound the breastplate by its rings to the rings of the ephod with a blue cord, so that it should lie on the decorated band of the ephod.  Then the breastplate would not come loose from the ephod, as Yahweh had commanded Moses.”

Here they speak in the plural they, as many artisans may have been involved in making the breastplate as er ethey HerYahweh had commanded Moses to do in chapter 28.  They made the breastplate with skilled work just like the ephod.  This breastplate was square with four rows of precious stones, corresponding to the twelve tribes of Israel with signet engravings.  There also were chains of golden twisted cords.  The breastplate was tied to the ephod with a blue cord in the two rings on its edges of his breastplate so that it would not come loose from the ephod.