A hardy stone that protects its bearer. Most curiously, its strength seems to depend on the wishes of its owner. If the bearer of one of these stones has a strong desire to protect another, then the stone will be so hard as to be almost unbreakable. But if it is then passed to an owner without such a focus, it can easily be smashed to dust. For this reason, it would seem that these stones are often mistaken as unremarkable rocks by most people who come across them.