The resurrection ring from Harry Potter and the Deathly Hallows, according to the book.

The original stone was given to the second brother by Death herself, but this is a good copy.

Two choices : one with the symbol engraved and another one with the symbole on top.

Turn the stone 3 times if you want to bring someone back from the dead.

*Might not actually bring the deads back… Might depends on the magic, the person, the material you use or the fact the story is fiction.