Mechanoluminescence

Mechanoluminescence is light emission resulting from any mechanical action on a solid.

• Fractoluminescence is caused by stress that results in the formation of fractures, that in turn yield light.
• Piezoluminescence is caused by pressure that results in elastic deformation and large polarization from the piezoelectric effect.^[1]
• Triboluminescence is nominally caused by rubbing, but sometimes occurs because of resulting fractoluminescence. It is often used as a synonym.^[2]

Mechanoluminescence can be produced through various means, such as ultrasound (e.g., causing crystals suspended in slurries to collide with one another and shatter).^[3] The related phenomenon of sonoluminescence differs in that it pertains to liquids.