Up to 10 minutes
You create a wall of ice on a solid surface within range. You can create a hemispherical dome or a 10' radius sphere, or you can shape a flat surface made of ten 10' square panels. Each panel must be connected to another panel. In any form, the wall is 1' thick and lasts for the duration.
If the wall cuts through a creature's space when it appears, the creature is pushed to one side of the wall and makes a Dex saving throw. If failed, the creature takes 10d6 cold dmg (1/2 dmg if successful). The wall has an AC 12 and 30 HPs per 10' section, and it is vulnerable to fire dmg. Reducing a 10' section of wall to 0 HPs destroys it and leaves behind a sheet of frigid air. A creature moving through the frigid air the 1st time must make a Con saving throw — if failed take 5d6 cold dmg (1/2 dmg if successful).
When you cast this spell using a spell slot of 7th level or higher, the damage the wall deals when it appears increases by 2d6, and the damage from passing through the sheet of frigid air increases by 1d6, for each slot level above 6th.
a small piece of quartz