Exodus 28

Aaron was equipped with:

• An ephod (apron), with shoulder suspenders of gold, twisted linen and colored yarn
• Two stones in gold filigree, each engraved with the names of six sons of Jacob, to be worn on the shoulder, attached by braided gold rope
• A 9" x 9" breastpiece, folded double and mounted with twelve precious stones, each engraved with the name of a tribe of Israel. This is to be hung from the shoulderpiece and the waistband of the ephod by gold rope. The breastpiece is to be used in making decisions
• Urim and Thummin, evidently for divination, to be carried in the breastpiece
• A collared blue robe, adorned with gold bells and colored yarn pomegranates. The bells protect Aaron on entering or leaving the presence of the Lord
• A linen turban, to which is attached over the forehead a gold plate labeled HOLY TO THE LORD
  
  Aaron and his sons also receive linen tunics, sashes and headbands, as well as undergarments to protect them from guilt
  
  To quote the Catholic Encyclopedia, "Urim is derived from the Hebrew for 'light', or 'to give light", and Thummim from 'completeness', 'perfection', or 'innocence'. In view of these derivations it is surmised by some scholars that the sacred lot may have had a twofold purpose in trial ordeals, viz. Urim served to bring to light the guilt of the accused person, and Thummim to establish his innocence." (http://www.newadvent.org/cathen/15224a.htm) The Urim and Thummim vanished with the destruction of the First Temple