When a priest casts this spell, he creates an invisible force field or barrier that blocks the entrance of animated or living mineral creatures. It is effective against elementals and creatures of elemental origin such as aerial servants, djinns, and mephits; golems and other constructs; creatures of living stone, such as galeb duhr or xorn; and objects, weapons, or armor animated by some outside force. It does not bar the passage of undead monsters, living creatures carrying inanimate material, or nonanimated minerals such as a giant-thrown boulder or a common rockslide. The antimineral shell moves with the caster, but if the caster tries to force it against a creature affected by this spell, the antimineral shell fails. The material component is a drop of some caustic solvent, such as acid from a black dragon.