Primary applications of luminescence include the use of fluorescent lamps, photon counting, LEDS, emissive displays, and systems for detecting X-rays or gamma rays. For x-rays and gamma ray detection, luminescent particles are excited by high energy photons, and the component of excitation energy is used to produce visible light. Additionally, luminescence can be used in lasers, phosphors, and thermoluminescence dating. Luminescence also occurs in certain minerals when exposed to UV or IR light, and these minerals can be identified. Thus, luminescence offers a wide array of uses for biological processes.