The Circle has its fair share of catastrophic astronomical events. Especially potent are the hellstone meteors, the result of the orbit of the planet passing near a ring of magnetically charged debris. Hellstone itself is a substance very similar to iron and had intense, magnetic properties.

Curiously though, it is magnetic only to itself and polarizes with a unique signature in the atmosphere of the planet. As a result, Hellstone compasses are often fashioned in pairs where they will only ever point to one another, effective up to nearly 1,000 miles.