From The Grey House, Book One:
The woman wore a silver chain with a large red stone. The stone was set in silver backing and had silver markings on it. To a casual observer, the markings probably looked like a random design. Natalia had seen a large picture of it in the Slayer journals and knew better. The one she found in the book had a fleur-de-lis that wrapped to the edge of the stone. This one did too, but the middle of the design was not the usual fleur-de-lis. The middle was a paw print. Natalia had a vague idea what the design meant, but knew exactly what the necklace itself meant.