The Amulet 'Heartstone'
+3 to health. It increases resistances: +30% poison and +30% disease. It
provides protection from the effects of experience drain and poisoning. It
gives its wielder regeneration. It cannot be damaged by any means. When
worn and activated, it heals you a very large amount, eliminates cuts and
stunning, recharging every 450+d100 turns.
Level 65, Rarity 40, 0.3 lbs, 42500 Gold.

(EyAngband 0.5.2)