Only about 25% to 35% of diamonds exhibit some degree of fluorescence in reaction to long-wave UV light. More than 95% of these diamonds fluoresce blue. A rare few fluoresce other colors such as yellow or green.
Boron impurities are what cause the diamond to turn blue. Natural fancy blue diamonds get their color from boron being present while they are formed, too.
Diamond fluorescence refers to the intensity of a colored glow (usually blue) that is visible when a diamond is exposed to UV light. In some instances, diamonds with strong fluorescence may look milky and lifeless in daylight, but in most cases, the appearance of a diamond with strong fluorescence is rarely affected.
In most cases, diamonds fluoresce blue. This cancels out the slightly yellowish color in most diamonds, resulting in a whiter appearance in sunlight. In artificial light, there's little UV intensity more than a few inches from the light source.
Black light test:
When you place a real diamond underneath an ultraviolet light, the stone with fluorescence in it will turn blue. But it's important to know that this will only happen with about one-third of all diamonds. A fake diamond, on the other hand, will almost never look blue under a black or UV light.
What is diamond fluorescence? Fluorescence is the glow you sometimes see when an object emits visible light. Some diamonds fluoresce when they are exposed to long-wave ultraviolet (UV) rays from sources like the sun. This can cause them to emit a bluish light or more rarely, a yellow or orangy light.
Fluorescence occurs in some diamonds when they are exposed to the concentrated radiation of a UV lamp. Submicroscopic structures in the diamonds cause them to emit a visible light, a fluorescence, which is commonly blue in colour.
Fluorescent diamonds in the colorless and near-colorless range (D-H) will look bluish under UV light. They also can appear hazy or oily in appearance. So, if you're thinking about buying a fluorescent diamond, remember that fluorescence and color counteract each other.
The most obvious difference is, of course, colour. Blue diamonds get their colour from trace amounts of boron atoms in the crystal structure. The amount of boron present determines how intense the blue colour is. Meanwhile, white diamonds are typically colourless due to the absence of any hue-inducing impurities.
A real diamond will reflect both rainbow colors as well as white light. If you only get one of the two, then the diamond isn't real.
The perfect diamond is colorless, and any hint of color makes a colossal difference in the quality of your diamond. As you move down the color scale, tinges of yellow or brown appear in the stones, and this colored tint reduces the value and quality of the diamond.
Colorless diamonds are “icy” white, and near-colorless diamonds do not show any obvious body color to most observers. Ideal cut diamonds appear whiter than average cuts and diamond color is more noticeable from the side where the influence of light return does not impact your perception of color.
Diamonds form naturally in all different colors. Shades of light yellow are the most common, though all the colors of the rainbow and white, black, and gray can be found. The gemologists who grade diamonds use a list of 27 color hues across the rainbow spectrum.
Kadakia said that less than 2 percent of diamonds discovered in the world are blue (the color comes from the presence of boron in the diamond). Only 10 percent of all blue diamonds discovered are larger than a carat — so the Oppenheimer Blue is a highly prized freak of nature.
The way that diamonds reflect light is unique: the inside of a real diamond should sparkle gray and white while the outside should reflect a rainbow of colors onto other surfaces. A fake diamond, on the other hand, will have rainbow colors that you can see inside the diamond as well.
Visit A Trusted Jeweler
Many jewelers will appraise your stone free of charge and experts will often be able to tell immediately if your diamond is authentic or not. If your stone came with a certificate, your jeweler should be happy to take a look at it and tell you whether it is from a trustworthy source.
Genuine diamonds do not sparkle in rainbow colors inside of the stone. Instead, the inside of real diamonds sparkles in tones white and gray. The play on light in the diamond is brilliance. One factor that determines a diamond's level of brilliance is the cut.
Blue diamond is a type of diamond which exhibits all of the same inherent properties of the mineral except with the additional element of blue color in the stone. They are colored blue by trace amounts of boron that contaminate the crystalline lattice structure.
Diamond fluorescence is not necessarily a bad thing. In fact, it can be a good thing in some cases. For example, diamonds with blue fluorescence can appear whiter and brighter than diamonds without fluorescence. However, in other cases, fluorescence can make a diamond appear hazy or milky.
An ideal cut diamond shows only a few intensely bright flashes in direct sunlight. A diamond that actually looks good in sunlight splits those few flashes up into ten or twenty smaller sparkles.
A pure and natural diamond is known to produce a blue glow when exposed to black light. The impure ones have certain chemical impurities that trigger the glow of other colors like green, white, red, and yellow when diamonds are exposed to ultraviolet light.
Diamond value is based (in part) on the absence of color
Diamond color is important: Most diamonds used in engagement rings are near-colorless with hints of yellow or brown. All things being equal, the more colorless a diamond is, the rarer it is, and this rarity will be reflected in its price.
Red diamonds are the rarest of the colored diamonds, with only 20-30 existing in the entire world. They get their beautiful red color from a rare process during their formation, which changes the crystal structure of the diamond and causes light to pass through it differently than colorless diamonds.
Keep the diamond clean.
This is probably the most important (and affordable) tip. A diamond that's dirty will not sparkle. Diamonds have an affinity for grease, so it's important to clean them regularly. Find out how to keep your diamond clean.