Iconic shards were used to power House icons. When a House constructed an icon, that icon was placed on Nishnatoba. House members travelled to the plane with iconic shards and used them to power the icon for their House. Iconic shards sometimes spontaneously appeared and fell to the ground when a creature or denizen was slain.
There were three sorts of shards, listed in order of weight: jagged (giving off a white glow), chipped (blue glow), and smooth (purple glow). The heavier the shard, the more power to an icon.