As of build 10.0.0, certain dungeon bosses are able to drop pieces of treasure sets that are unique to the dungeon. The individual treasures and complete sets currently have no official use. Due to their high feed power (along with the soulbinding of the untiered items), many players choose to feed them to their pets.
NOTE: Some treasures say “double-click to equip” when you hover over them. Whether this is a sign that treasures will later be used as equipment, or if it is just an error in coding, is not known.