Mermaid's Bed?

This is my first entry for Tiny Tuesday. I didn't take any photos earlier today so had a hunt around the house and found this. It's quite tiny, being about 3cm long so I hope that counts.
It is a common ormer shell, Haliotis lamellosa, which I picked up from the sandy seabed when I was snorkelling in Greece a few years ago. The extra is the inside of the shell which has a beautiful coating of mother of pearl. The photos really don't do it justice. 
They are quite popular with small children when I explain that they are the beds of tiny mermaids.