Actorius

An actorius is a non-precious mineral stone found in the gizzard of capons (young, castrated roosters). In magic it is believed to be an effective amulet, granting the wearer a heightened sense of courage and boldness. These properties are unproven.

In Michael Moorcock's fantasy series about Elric of Melniboné, the crown jewels of the Emperor of Melniboné include the Ring of Kings set with a rare Actorios stone. The jewel's magical nature is apparent by the swirling form visible in its depths. The Ring of Kings confers on its wearer the right to call on magical aid as well as the right to sit on the Ruby Throne. A legend says that if someone should ever sit on the throne without wearing the ring, the destruction of Melniboné would result.