Extreme heat and pressure change rock into metamorphic rock.
Gneiss rocks gneiss rocks gneiss rocks are metamorphic.
Extreme heat and pressure change rock into gneiss.
What changes rock into gneiss?
  weak heat and low pressure
  The bending of a ray of light
  extreme cold and pressure
  heat is produced
  movement of tectonic plates
  tectonic plates being pushed together
  extreme heat and pressure
  extreme heat and no pressure