The Mattock of Nain (+12, 10d19)
+6 to strength, perception, infravision and tunneling. It increases
resistances: +40% acid, +30% dark and +30% disenchantment. It modifies
damage: x2 vs. humanoids and x2 acid brand. It is vulnerable to damage by
disenchantment. When wielded and activated, it melts a wall square to
floor, recharging every 10+d10 turns.
Level 60, Rarity 20, 25.0 lbs, 15000 Gold.

(EyAngband 0.5.2)