Amethyst... because it's silicon dioxide
It is called vaporization. Vaporization is the phase transition from a liquid to a gas by means of evaporation or boiling. Evaporation occurs at temps below the boiling point and occurs on the liquids surface. Boiling is a rapid vaporization that occurs above the boiling temp and below or at the liquids surface.
Mass of the object m = 25 kg
Coefficient of friction Uk = 0.15
Frictional force Ff = Uk x F => Ff = Uk x m x g
Ff = 0.15 x 25 x 9.8
Frictional Force Ff = 36.75 N