"The old man wore a breastplate"
Breastplates were traditionally worn by High Priests in Judaism, with twelve precious stones to represent the twelve tribes of Israel. Urim and Thummin were contained in a fold. The prototype is described in Exodus:
And 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 28:15-30