The Arkenstone of Thrain Permanent light-source (radius 3). It increases resistances: +20% light and +20% dark. It provides protection from the effects of experience drain. It gives its wielder see invisible. It cannot be damaged by any means. When worn and activated, it detects everything of interest on the panel, recharging every 30+d30 turns. Level 50, Rarity 50, 0.5 lbs, 25000 Gold. (EyAngband 0.5.2)