Up to 10 minutes
A nonmagical wall of solid stone springs into existence at a point you choose within range. The wall is 6" thick and is composed of ten 10'x10' panels. Each panel must be contiguous with another panel. Alternatively, you can create 10'x20' panels that are only 3" thick.
If the wall cuts through a creature's space when it appears, the creature is pushed to one side of the wall (your choice). The wall doesn't need to be vertical or rest on any firm foundation, but it must be solidly supported by existing stone. Each panel has AC 15 and 30 HPs per inch of thickness. Reducing a panel to 0 HPs destroys it and might cause connected panels to collapse (at the DM's discretion).
If you maintain your concentration on this spell for its whole duration, the wall becomes permanent and can't be dispelled. Otherwise, the wall disappears when the spell ends.
a small block of granite
Verbal Component (Alternative):
By my magic, an arcane call, I summon forth a solid stone wall.