The Hope of Erethor
This large shell, twenty feet long from end to end, is the second great treasure taken from the Violet Citadel of Ibon-Sul. When touched by any evil creature, the shell is virtually immovable, yet when touched by creatures aligned with goodness, the shell becomes lighter than air, levitating ten feet off the ground.
The shell gives off its own, dim azure light. A simple, airy music can be heard when standing beside the shell; the sound, similar to a soprano singing far away in an otherworldly tongue.