Breastplate

Boyd’s Bible Dictionary:

The breastplate of the high priest (Ex. 28:1515And thou shalt make the breastplate of judgment with cunning work; after the work of the ephod thou shalt make it; of gold, of blue, and of purple, and of scarlet, and of fine twined linen, shalt thou make it. (Exodus 28:15)), was of embroidered stuff, some 10 inches square; its upper corners fastened with gold or lace to the ephod, its lower to the girdle (Ex. 28:2828And they shall bind the breastplate by the rings thereof unto the rings of the ephod with a lace of blue, that it may be above the curious girdle of the ephod, and that the breastplate be not loosed from the ephod. (Exodus 28:28)). Adorned with 12 precious stones (Ex. 28:12-2912And thou shalt put the two stones upon the shoulders of the ephod for stones of memorial unto the children of Israel: and Aaron shall bear their names before the Lord upon his two shoulders for a memorial. 13And thou shalt make ouches of gold; 14And two chains of pure gold at the ends; of wreathen work shalt thou make them, and fasten the wreathen chains to the ouches. 15And thou shalt make the breastplate of judgment with cunning work; after the work of the ephod thou shalt make it; of gold, of blue, and of purple, and of scarlet, and of fine twined linen, shalt thou make it. 16Foursquare it shall be being doubled; a span shall be the length thereof, and a span shall be the breadth thereof. 17And thou shalt set in it settings of stones, even four rows of stones: the first row shall be a sardius, a topaz, and a carbuncle: this shall be the first row. 18And the second row shall be an emerald, a sapphire, and a diamond. 19And the third row a ligure, an agate, and an amethyst. 20And the fourth row a beryl, and an onyx, and a jasper: they shall be set in gold in their inclosings. 21And the stones shall be with the names of the children of Israel, twelve, according to their names, like the engravings of a signet; every one with his name shall they be according to the twelve tribes. 22And thou shalt make upon the breastplate chains at the ends of wreathen work of pure gold. 23And thou shalt make upon the breastplate two rings of gold, and shalt put the two rings on the two ends of the breastplate. 24And thou shalt put the two wreathen chains of gold in the two rings which are on the ends of the breastplate. 25And the other two ends of the two wreathen chains thou shalt fasten in the two ouches, and put them on the shoulderpieces of the ephod before it. 26And thou shalt make two rings of gold, and thou shalt put them upon the two ends of the breastplate in the border thereof, which is in the side of the ephod inward. 27And two other rings of gold thou shalt make, and shalt put them on the two sides of the ephod underneath, toward the forepart thereof, over against the other coupling thereof, above the curious girdle of the ephod. 28And they shall bind the breastplate by the rings thereof unto the rings of the ephod with a lace of blue, that it may be above the curious girdle of the ephod, and that the breastplate be not loosed from the ephod. 29And Aaron shall bear the names of the children of Israel in the breastplate of judgment upon his heart, when he goeth in unto the holy place, for a memorial before the Lord continually. (Exodus 28:12‑29)).

From Manners and Customs of the Bible:

1. In the earliest times helmets were made of osier or rushes, and were in the form of bee-hives or skull-caps. The skins of the heads of animals were sometimes used. Various other materials were employed at different times. The ancient Egyptian helmet was usually made of linen cloth quilted. It was thick and well padded, sometimes coming down to the shoulder, and sometimes only a little below the ear. The cloth used was colored green, or red, or black. The helmet had no crest, but the summit was an obtuse point ornamented with two tassels. The Assyrian helmet was a cap of iron terminating above in a point, and sometimes furnished with flaps, covered with metal scales and protecting the neck. The Philistine helmet, as represented on ancient monuments, was of unique form. From the head-band there arose curved lines, by which the outline of the helmet was hollowed on the sides and rounded on top.
2. For the body, the skins of bents were probably the earliest protection in battle. Felt or quilted linen was also used subsequently. The ancient Egyptians had horizontal rows of metal plates well secured by brass pins. The ancient Assyrians had scales of iron fastened on felt or linen. Iron rings closely locked together were likewise used by different nations. Scales made of small pieces of horn or hoof were also used. Sometimes a very serviceable armor was made of small plates of metal, each having a button and a slit, fitting into the corresponding slit and button of the plate next to it. It is supposed that Ahab had on armor of this sort when he was slain; the “joints of the harness” being the grooves or slits in the metallic plates, or the place between, where they did not overlap (1 Kings 22:34; 234And a certain man drew a bow at a venture, and smote the king of Israel between the joints of the harness: wherefore he said unto the driver of his chariot, Turn thine hand, and carry me out of the host; for I am wounded. (1 Kings 22:34) Chron. 18:33). Goliath’s “coat of mail” was scale armor (shiryon kaskassim, “armor of scales”). This kind of armor consisted of metallic scales rounded at the bottom and squared at the top, and sewed on linen or felt. The Philistine corselet covered the chest only. On the bas-relief at Nineveh are seen warriors with coats of scale armor which descend to the knees or ankles. In one of the palaces Mr. Layard discovered a number of the scales used for this armor. Each scale was of iron two to three inches long, rounded at one end and squared at the other, with a raised or embossed line in the center, and some were inlaid with copper. At a later period the Assyrian armor was made of smaller scales, which were pointed and ornamented with raised figures, and the coat of mail reached no lower than the waist.