Fluorescent minerals emit visible light when exposed to
Biofluorescent marine organisms
Fluorescence is the emission of
light by a substance that has absorbed light or other
electromagnetic radiation. It is a form of
luminescence. In most cases, the emitted light has a longer
wavelength, and therefore lower energy, than the absorbed radiation. The most striking example of fluorescence occurs when the absorbed radiation is in the
ultraviolet region of the
spectrum, and thus invisible to the human eye, while the emitted light is in the visible region, which gives the fluorescent substance a distinct color that can only be seen when exposed to
UV light. Fluorescent materials cease to glow nearly immediately when the radiation source stops, unlike
phosphorescent materials, which continue to emit light for some time after.
Fluorescence has many practical applications, including
medicine, chemical sensors (
dyes, biological detectors, cosmic-ray detection, and, most commonly,
fluorescent lamps. Fluorescence also occurs frequently in nature in some minerals and in various biological states in many branches of the animal kingdom.