Scroll of Shattering

Turns every wall type terrain in a wide radius into green crystal, the same stuff as that produced by a staff of obstruction. The crystal will melt over time. Destroys anything tunneling would destroy, except it turns into green crystal instead (walls, doors, sentinels, turrets including pesky flame turrets and the 'gauntlet' key puzzle which surrounds you with turrets, etc). Walls at the edge of the map will instead be transformed into non-melting crystal of the type sometimes found in crystal formations.