glow in the dark stones is right

Of not emitting substance contained in the relevant saying, but certainly not the composition of the light-emitting jade because jade is actually a crystalline form of aluminum oxide, which is not illuminated.
There are two possible common luminous minerals, one fluorescent substance, one phosphorescent substance. Only when a fluorescent substance is excited (visible light, ultraviolet, or other types of radiation) will light, the excitation source is removed not shine, such as our common fluorescent; glow in the dark stones was removed over a period of time after the excitation source is still light, such as zinc sulfide. Natural substance capable of emitting light often contain radioactive elements, to which fluorescent substance or a glow in the dark stone provides the radiation, so harmful to people. There is the case of a light, that is, the phenomenon of energy release of radioactive material, such as radium and radon, which is a radioactive element itself emits light.