IIRC an int/arcana check says the runes are githyanki though?
Its iron and has pulsating runes on it with something inside. Im guessing its infernal iron (black) with a contract in there.
Either that or im way off and it holds a mindflayer tadpole that they can control or somethin haha. Looks like a puzzle box though. But all I have is a hammer on that one so it looks like a nail