Moonstone is a type of Feldspar that diffracts light, giving it a luminous look. The ancient Romans considered moonstone to be solidified moonlight.
Moonstone contains aluminum, which should not be ingested. Tumbled Moonstone is safe to wear and hold. It is also safe to use to make elixirs using a tumbled stone, however, the tumbled stone must be removed. Do not crush Moonstone to add to an elixir. Always wear a mask when grinding or engraving Moonstone (which you should anyway) taking care not to inhale Moonstone dust.