Mermaid's Purse Necklace

Known as a mermaid's purse, this is actually the egg case of a dogfish.
It is always a little bit magical to find one of these on the beach, although the real ones dont usually contain a baby dogfish when you find one.
Here the case is represented in copper, and the tiny dogfish in silver, hanging on a silver chain.
In the main photograph above the jewellery is on the left, the real mermaid's purse on the right.