Real Stones Used for the Urim and Thummim in ancient times. Stones come in a plastic bag with information about them. Bag size is about 6 1/2 inches by 5 7/8 inches. Stone size about 1 1/2 by 1 1/4 inches. History: Urim and Thummim Exodus 28:30 “And thou shalt put in the breastplate of judgment the Urim and Thummim; they shall be upon Aaron’s heart when he goeth in before the Lord.” The Urim and Thummim was God’s way of answering His people. Urim (אורים) means “light” and Thummim (תמים) probably means “darkness/truth.” Possible recreation; Urim, white stone means no for an answer, and Thummim black stone means yes.