"A sharp piece of glass.
Make sure not to cut yourself."
The Mirror Shard is an item found in Prisoners of the Elder One. It is located in the Dirty Room, requiring both the Broom and Dustpan if Camelia is in the room, and is used to cut both web and skin, the former in Aktarise's domain and the latter for summoning Aubrey. It can also be used to get through the lasers guarding the Yellow Gem, and is given to Valda for repairing her mirror.