A glow, usually of a bluish color, that emanates from some diamonds when exposed to ultraviolet light. Strong fluorescence is not desirable, but faint fluorescence does not affect the appearance of a diamond.

the emission of light of longer wavelength , usually visible, by a substance when irradiated by light of shorter wavelength, usually ultraviolet

The tendancy to "Glow" when exposed to UV light, described as... Here's an article by the President of the GIA you might find interesting, but basically this is a non-event and should not rule out a fine diamond Inert or None, Faint, Medium, Strong Very strongl In the "real world" up to medium is no problemo...

A form of luminescence in which substances are capable of absorbing light of one wavelength or colour and, in its place, emitting light of another wavelength or colour. This forms the basis for fluorescent lighting.

A measurement of a diamond's emission of light when under ultraviolet light or x-rays, from none to very strong. Some diamonds emit blue or yellow fluorescence.

a process by which substances give off light or another form of electromagnetic radiation when they absorb energy.

The emission of visible light by a substance which is exposed to ultraviolet light.

The process of a material emitting visible light when it is subject to ultraviolet light. For example, diamonds under ultraviolet light will often emit a visible light of a blue hue.

The emission of a photon of visible light by an excited atom or molecule.

It is the process of a material which emits visible light when it is subject to ultraviolet light. As an example, diamonds under UV light often emits a visible light of a blue hue.

A visible light occasionally emitted from diamonds when exposed to ultraviolet light, usually blue in colour.

emission of visible light from a material following its exposure to ultraviolet radiation.

The property of some materials to glow when subjected to Ultra-violet light. The materials degrade the UV wavelengths into longer and therefore visible reflected rays. See also Phosphorescence.

Light resulting from the action of ultraviolet or other forms of energy on phosphors. Fluorescence occurs only while energy is being absorbed by the fluorescing material.

The emission of electromagnetic radiation, especially that of visible light, as a result of the absorption of electromanetic radiation, and persisting only as long as the stimulating radiation is continued.

Emission of energy as visible light.

The property of emitting electromagnetic radiation usually as visible light resulting from external stimulation with another light (or energy) source and occurring only during the absorption of radiation from some other source.

The emission of electromagnetic radiation following absorption of shorter wave length light.

luminescence in which light of a visible color is emitted from certain substances, called phosphors, when irradiated by electromagnetic radiation, especially ultraviolet light.

Occurs when matter absorbs light then emits light at a longer wavelength.

stamp paper or inks containing fluorescent brighteners that glow brighter while exposed to short or long wave ultraviolet light. There is no afterglow, and fluorescent papers usually glow a bluish-white. Stamp inks containing fluorescent brighteners can glow in a variety of colors.

the colored glow emitted by some gem-quality diamonds when exposed to ultraviolet light. Fluorescence is usually blue, but can be any color. Strong fluorescence can make a high-quality diamond look hazy or cloudy in daylight, which diminishes the diamond's radiance. However blue fluorescence can improve a lower quality diamond by balancing out yellow tones and giving the diamond a clearer, whiter look in daylight. The famous Hope Diamond had an unusual red fluorescence, which contributed to its reputation for being cursed.

The ability of a substance, such as paper or ink, to absorb ultraviolet light waves and reflect them as visible light.

A property of some materials where electromagnetic energy of one wavelength is absorbed and then re-emitted at another (usually longer) wavelength.

The property in many diamonds that makes them glow in an environment rich in ultraviolet light. Diamonds can fluoresce in a number of colors, but generally all but blue are to be avoided. Faint to medium fluorescence is rarely detected under ordinary lighting conditions. Strong or very strong fluorescence may make a diamond appear “milky” or “oily”, especially in sunlight. Blue fluorescence may enhance the color of diamonds rated “H” in color or below (I,J, etc.) by hiding their yellow tint. Diamonds rated D-F with medium+ fluorescence may sell at a discount.

A glow or color visible under ultraviolet light.

Property of emitting light while exposed to light. The wavelength of the emitted light is longer than that of the absorbed light. Fluorescent substances that simultaneously absorb and emit light appear luminous. Fluorescence in tissues is induced by staining tissue with fluorescent dyes.

Longer wavelength emissions which can result form excited electron energy, results in a glowing light.

Emission of visible light by a substance, such as a mineral, that is currently exposed to ultraviolet light and absorbs radiation from it. The light appears in the form of glowing, distinctive colors. The emission ends when the exposure to ultraviolet light ends. Minerals describes as fluorescent have the ability to fluoresce.

Emission of radiation at one wavelength in response to the absorption of energy at a different wavelength. Some lunar materials fluoresce. Most do not. The process is identical to that of the familiar fluorescent lamps.

the emission of electromagnetic radiation as the result of exposure to some other radiation, which emission ceases when the stimulus that produces it ceases to act on the emitting substance. Thus light passing through a gas, may change the energy state of the atoms and cause them to emit light of a different wavelength.

The emission of electromagnetic radiation, especially light, resulting from bombardment or a substance with other forms of electromagnetic radiation.

the emission of light (or other electromagnetic radiation of longer wavelength) by a substance as a result of absorption of other radiation. The emission continues only as long as the stimulus producing it continues and persists with a half-life of less than about 10-8 second.

This is the emission of electromagnetic radiation such as visible light caused by the absorbtion of incident radiation.

The emission of light at a particular wavelength following excitation of the electron by absorption of light at another, shorter, wavelength.

The emission of light of a particular wavelength resulting from absorption of energy typically from light of shorter wavelengths.

light emitted during absorption of radiation of some other (invisible) wavelength

Light that is emitted a short period of time after an electron has been excited.

A glow, often bluish in hue, that emanates from some diamonds when they're bathed in ultraviolet light. Avoid high degrees of fluorescence; faint to medium fluorescence, however, usually does not change the diamond's appearance. The effect of fluorescence depends on the combination of the color of the stone in question and the strength of the fluorescence. Faint fluorescence has very little effect on a stone of any color. Medium blue fluorescence and strong blue fluorescence can have a positive effect on stones of low color (J or worse). The fluorescence actually has the effect of making the stone look closer to near colorless. On stones of high color (D-G), strong or medium blue fluorescence can make the stone look milky instead of colorless or near colorless

Energy emitted as photons when excited molecules return to their ground state.

The property of giving off light at a particular wavelength ("emission wavelength") when illuminated by light of a different wavelength ("excitation wavelength").

A physical phenomenon whereby an atom of a material absorbs a photon of light an immediately emits a photon of longer wavelength. If there is a significant delay the phenomenon is called phosphorescence rather than fluorescence. It is interesting that "phosphors" used in lamps exhibit "fluorescence," not "phosphorescence”.

relaxation route producing radiation from short-lived (10 microseconds) excited states.

The slow emission of longer wavelength light following the absorption of shorter wavelength radiation. Fluorescence is common with aromatic compounds with several rings joined together. Phosphorescence is similar but may persist long after the stimulating radiation is extinguished.

Fluorescence is the ability of a substance to glow (luminescence) when exposed to ultraviolet light.

An illuminating blue hue that glows from the surface when a diamond is lit under ultraviolet light.

Fluorescence is property in which light or other radiation is emitted from an object. When exposed to ultraviolet light a diamond may exhibit a more whitish yellowish or bluish tint which may imply that the diamond has a property called fluorescence. Fluorescence is not considered a grading factor only a characteristic of that particular diamond

Normally invisible wavelengths of light that become "visible" when exposed to ultraviolet radiation. Gems or pearls that exhibit colour under ultraviolet light, colour not normally seen in normal light, are exhibiting "fluorescence".

The ability of some gems to appear a different color when viewed under ultraviolet light. If or not a stone has fluorescence is a valuable aid in gem identification.

The intangible element in a diamond that gives some diamonds a (generally) blue or yellow glow when exposed to ultraviolet light. (See Frequently asked questions)

Some diamonds may release a bluish color when exposed to ultraviolet light. Subtle fluorescence does not affect the appearance or the value of a diamond, and is not visible under normal light conditions.

Luminescence caused by the absorption and almost immediate release of radiant energy. When radiant energy, such as ultraviolet light, shines on a fluorescent object, the electrons within the object are kicked into an excited state. This state, however, is very unstable and the absorbed energy is quickly released as light. Fluorescence stops when the source of radiant energy is removed. Compare with phosphorescence. See examples of mineral fluorescence.

A diamond's reaction to ultraviolet (UV) light, causing the stone to glow in various colors.

Mostly blueish glow of a Diamond in high ultraviolet lighting conditions. Ratings: none, faint, slight, medium, strong blue. Strong blue fluorescence may cause the diamond to appear oily in daylight.

This refers to an effect seen in diamond when exposed to long wave ultra violet light. Fluorescence is undetectable in most lighting conditions and can only be seen when placed under an intense and direct ultra violet lamp. Fluorescence has no deleterious effect on the integrity of the diamond. Some prefer Fluorescence in diamonds, others do not. It is a matter of personal taste. Fluorescence in lower color diamonds posses a unique desirability as they will make diamonds appear whiter than their actual color grade.

The process whereby colours absorb radiant power at one wavelength and immediately re-emit it at another (usually longer) wavelength.

The absorption of light at one wavelength and its re-emission at a longer wavelength. Fluorescence plays an important role in the perceived color of many objects: the unnatural brightness of "day-glo" paints is due to fluorescence.

Electrons absorb energetic radiation (for example ultraviolet light) raising an electron to a higher "Bohr" orbit. The energized electron soon drops down in a series of steps through lower energy states and in the process releases photons at lower energy states corresponding to visible light. The bright color occurs because the photons are concentrated in a narrow range of wavelengths.

Often mis-spelt as flourescence by those who should know better. The emission of visible light displayed by some diamonds and other gems when viewed in ultra-violet or other light. Cause frequent concern by consumers on discovering that one diamond or more in a cluster glow under "disco" lighting.

Förster excitation transfer (dipole-dipole excitation transfer)

The absorption of a photon of one energy, or wavelength, and re-emission of one or more photons at lower energies, or longer wavelengths. [More Info: Field Guide

A bluish glow which emanates from some diamonds when exposed to ultraviolet light. Strong florescence is not desirable, but small amounts will not detract from the appearance of a stone.

Fluorescence means that a diamond will glow usually in blue under UV light when illuminated. The effect is like a white shirt at a disco party, it glows. Fluorescence can range from faint to very strong and can make a yellowish diamond look white or colourless

The phenomenon of emitting light upon absorbing radiation of an invisible wavelength.

The ability of some materials, such as phosphors, to convert ultraviolet energy into visible light.

fluorescence is the property of certain molecules, or fluorophores, to absorb light at one wavelength and emit a light at a longer wavelength.

If a mineral is put under ultra-violet light and the color changes and seems to glow, the property of fluorescence is demonstrated.

When exposed to ultraviolet light, about half of all diamonds will display fluorescence. The amount of fluorescence determines the level to which it effects value. Fluorescence is graded from None to Extreme, with several steps in between, and it will be indicated on the stone's certificate.

An effect that is seen in some gem-quality diamonds when they are exposed to long-wave ultraviolet light (such as the lighting frequently seen in dance clubs). Under most lighting conditions, this fluorescence is not detectable to the eye. However, if a diamond is naturally fluorescent, it will emit a soft colored glow when held under an ultraviolet lamp or "black light." Fluorescence is not dangerous to the diamond or to the wearer; it is a unique and fascinating quality that occurs naturally in a number of gems and minerals. For additional information on the nature of fluorescence and its effect on diamonds.

The re-emission of light energy at a lower frequency by an absorber illuminated with optical energy. The response is usually immediate and on order 1 to 3% of the incident intensity.

The property that certain objects have of giving off radiation under the influence of incident light.

The light a gas gives off due to stimulation by light from another source. In comets, the molecules in the coma and gas tail give off light in response to sunlight.

The neon-like glow observed in some gems when they are irradiated with UV light.

A glow, usually of a bluish color, which emanates from certain diamonds when exposed to ultraviolet light. Strong fluorescence should be avoided, but faint fluorescence usually does not affect the appearance of a diamond.

The emission of light from a substance caused by exposure to radiation from an external source.

When exposed to ultraviolet light, a diamond may exhibit a more whitish, yellowish or bluish tint, which may imply that the diamond has a property called fluorescence. The untrained eye can rarely see the effects of fluorescence. Diamond grading reports often state whether a diamond has fluorescent properties. Fluorescence is not considered a grading factor, only a characteristic of that particular diamond

A word coined by George Stokes in 1852 which describes light emission induced during excitation.

The emission of light or other electromagnetic radiation at longer wavelengths by matter as a result of absorption of a shorter wavelength. The emission lasts only as long as the stimulating irradiation is present.

The absorption of light of one wavelength and re-emission of it at another wavelength; especially the conversion of ultraviolet into visible light.

Phenomenon which occurs when high-energy radiation is absorbed by a molecule (fluorochrome) and when this molecule emits light of a longer wavelength than that absorbed (Stoke's shift).

Emission of light by excited molecules as they revert to the ground state. http://www.everythingbio.com/glos/definition.php?word=fluorescence

The ability of certain gems to glow when heated in low-light situations.

instantaneous re-emission of light of a greater wave length than that light originally absorbed.

The process in which molecules or matter absorb high energy photons and then emit lower energy photons. The difference in energy causes molecular vibrations.

Emission of electromagnetic radiation that is caused by the input of energy into the emitting body and which ceases abruptly when the excitation source is removed.

A process by which certain pigments or materials can be made to appear to self illuminate when exposed to UV light. See Also: Ultra Violet

Fluorescence is property in which light (or other radiation) is emitted from an object. Many stones (including some diamonds) flouresce when exposed to ultraviolet light.

The glow induced in a material when bombarded by light of radiation.

A term used to describe the light emission given off by excitation of phosphors with Ultra -Violet light.

EGL rates fluorescence on a scale from NONE to VERY STRONG. Fluorescence refers to the visible light a diamond emits while under an ultraviolet light. Most often, the light emitted is blue, but other hues are possible. If fluorescence is rated higher than FAINT and the color is one other than blue, it will be noted on the certificate.

The luminescence exhibited in certain diamonds when exposed to ultraviolet light or strong sunlight. Fluorescence is most commonly blue in color, but can also be a variety of other colors.

An optical phenomenon that occurs when light absorbed by a material creates a molecular excitation that causes the material to re-emit light as a different wavelength.

fluorescent; fluorescent compound. A fluorescent substance absorbs short wavelength radiation and re-emits it as radiation with a longer wavelength in a very short time.

Fluorescence is a form of lumination created when a diamond is exposed to low or high wave ultraviolet radiation. Fluorescence is present in some degree in most diamonds.

the property by which a substance, under the effect of light, emits a different luminous radiation.

Under different rays, ultraviolet, cathode, or x-ray some diamonds fluoresces different colors.

the luminescence shown when irradiated by ultra-violet light.

Light emitted from a fluorophore (fluorescent molecule) as a result of excitation. The excitation wavelength (color) is different that the emission wavelength. This difference is known as the stokes shift. The emitted light is detected in a specialize detector like the PerkinElmer Wallac Victor. Most fluorophores give a simple emission that is about 1 picosecond after excitation while time-resolved fluorescence emits after a microsecond. Fluorescence is best detected with either the black or natural filter plates.

Fluorescence is a form of lumination that is created when a diamond is exposed to low or high wave ultraviolet radiation. Faint fluorescence will rarely detract from a diamond's beauty and cannot normally be seen or separated by the naked eye. Strong fluorescence can sometimes improve the appearance of diamonds that possess colour.

The luminescence that is caused by the absorption of radiation at one wavelength followed by nearly immediate reradiation usually at a different wavelength. Fluorescence in diamonds is an act of nature, and occurs randomly in diamonds.

A bluish glow within the diamond when exposed to ultraviolet light. Some people like fluorescence and some don't. In any case, strong fluorescence should be avoided.

The spectral emission of long wave radiation such as visible or infrared illumination by some materials when stimulated shorter wave radiation.

Fluorescence is the light that is emitted from a diamond when subjected to ultraviolet rays. This fluorescent glow is not always considered when grading a diamond for quality (using the standard Four C's); it is an inherent characteristic of a diamond (or stone).

An optical process by which energy is transferred from a certain range into a a longer wavelength range.

The emission by a material of light radiation at a longer wavelength, as a result of the absorption of some other radiation of shorter wavelengths. One example of this is when visible light is emitted as a result of the excitation of ultraviolet light.

The emission of light of one wavelength after being exposed to light of a different wavelength.

A property possessed by diamonds, fluorspar, uranium glass, sulphide of calcium, and many other substances, of glowing without appreciable rise of temperature when exposed to ultra-violet rays, cathode rays, X rays, etc. This fluorescent glow is not always considered when grading a diamond for quality (using the standard Four C's); it is an inherent characteristic of a diamond.

The property of changing the wavelength of radiation to one in the visible range; for example, the visible wavelengths emitted by a material when excited by invisible radiation (such as X-rays, ultraviolet rays or cathode rays), as well as by certain visible wavelengths. It is exhibited by ruby, kunzite, yellow-green synthetic spinel, some diamonds and opals, and many other substances.

Ability of a material to emit radiation, visible or invisible, upon receipt of certain stimulation such as ultra-violet rays or x-rays.

A physical process at which the materials pigments absorb light and re-radiate this light as a different colour, giving the colour of the material extra light or brilliance.

Process by which radiant flux of certain wavelengths is absorbed and re-radiated nonthermally at other, usually longer, wavelengths. This phenomenon creates colors that show an abnormal color response and are used for packaging and other dramatic effects.

a glow, usually of a bluish color, but sometimes in white, yellow, or yellow/orange hues, which emanates from certain diamonds when exposed to ultraviolet light.

The emission of radiation associated with the relaxation of an atom or molecule from an excited energy level to a lower (usually ground state) level. The emission can be in the visible or ultraviolet if an electronic transition is involved, or in the infrared if it is a vibrational transition. See also resonance fluorescence, laser-induced fluorescence, luminescence.

Fluorescence is a luminescence that is mostly found as an optical phenomenon in cold bodies, in which the molecular absorption of a photon triggers the emission of another photon with a longer wavelength. The energy difference between the absorbed and emitted photons ends up as molecular vibrations or heat. Usually the absorbed photon is in the ultraviolet range, and the emitted light is in the visible range, but this depends on the absorbance curve and Stokes shift of the particular fluorophore.