These shards, retrieved once every 100 years from the depths of the oceans by merfolk tribes, glow with a faint, blue light and are extremely cold to the touch.
When handling this item with bare skin, you must make a DC 15 CON save, or take 3d6 cold damage. As your skin touches the shard, the cold will creep up your arm like ice. If a creature is killed by the shard, they are frozen solid.