Quartz triboluminescence is the easiest form of triboluminescent light to observe. Quartz is the ... If you rub two pieces of quartz together or crush a quartz crystal, you' ... If it's true the light results from ionization of air, you might expect all forms of triboluminescence in the air to produce the same color of light. read more
These chipped fragments gets ignited due to the high temperature, and that is the light (fire) we see when quartz are struck together. Also happens when iron is rubbed against flint, when the iron fragments gets chipped and caught fire. This is one of the oldest methods of creating a fire without match or lighter. eg. read more