Most quartzite forms during mountain-building events at convergent plate boundaries where sandstone was deposited on a continental plate. There, the sandstone is metamorphosed into quartzite by the intense pressure of a plate collision and often by deep burial.
Compressional forces at the plate boundary fold and fault the rocks and thicken the crust into a mountain range. Quartzite is an important rock type in folded mountain ranges throughout the world.
