This creates a wall of stone with DR 12, HP 2.

Innate Attack (Crushing) 4d [106] 
    Area Effect (2 yard radius) [+50%] 
    Persistent [+40%] 
    Wall (Rigid, Shapeable) [+60%] 
    Extended Duration (Permanent) [+300%] 
    Magical [-10%] 
    Spell Components [-10%] 
        Must say "stone" in Latin 
Levels 2+ [+10/level] 
    Increase Area Effect by 1 step [+50%]