Diamond fluorescence is a phenomenon where some diamonds emit visible light when exposed to ultraviolet (UV) rays. Blue is the most common fluorescence color in diamonds, but other colors, such as yellow, orange, green, and red, are also possible. The intensity of fluorescence can vary from faint to intense.

Fluorescence is caused by certain impurities in the diamond’s crystal structure. These impurities can be trace amounts of boron, nitrogen, or hydrogen. When a diamond is exposed to ultraviolet rays, these impurities absorb the energy of the rays and then re-emit it as visible light.

The intensity of fluorescence is graded on a scale of none (N), faint (F), medium (M), strong (S), and very strong (VS). A gemologist uses a special fluorescence viewer instrument to determine the fluorescence grade.

How Does Fluorescence Affect the Appearance of a Diamond?

The effect of fluorescence on the appearance of a diamond can vary depending on the diamond’s color and the fluorescence’s intensity. In general, blue fluorescence can help to mask the yellow tint in some diamonds, making them appear whiter. However, yellow fluorescence can make a diamond appear hazy or cloudy.

In most cases, the fluorescence effect is subtle and not easily noticeable. However, in rare cases, strong fluorescence can significantly affect the appearance of a diamond. For example, a diamond with very strong blue fluorescence may appear to glow in the dark.

Does Fluorescence Affect the Value of a Diamond?

The effect of fluorescence on the value of a diamond is also variable. In general, diamonds with faint or medium fluorescence are not affected in value. However, diamonds with strong or very strong fluorescence may be worth slightly less than diamonds without fluorescence.

Some believe strong fluorescence can make a diamond appear hazy or cloudy. However, other people believe strong fluorescence can enhance a diamond’s appearance. Ultimately, the individual buyer’s preferences determine the value of a diamond with fluorescence.

How Is Diamond Fluorescence Graded?

The grade of fluorescence in a diamond is determined by a gemologist using a special instrument called a fluorescence viewer. The fluorescence viewer emits long-wave UV rays, and the gemologist observes the diamond’s reaction to the rays.

The grade of fluorescence is assigned on a scale of none (N), faint (F), medium (M), strong (S), and very strong (VS). The fluorescence grade is based on the intensity of the fluorescence and the color of the light emitted by the diamond.

What Factors Affect Diamond Fluorescence?

The intensity of diamond fluorescence is affected by a number of factors, including the type of impurity present in the diamond, the concentration of the impurity, and the size of the diamond.

Diamonds containing boron tend to have stronger fluorescence than those with nitrogen or hydrogen. The concentration of the impurity also affects the intensity of fluorescence. Diamonds with higher concentrations of boron will have stronger fluorescence than diamonds with lower concentrations.

The size of the diamond also affects the intensity of fluorescence. Larger diamonds tend to have stronger fluorescence than smaller diamonds. This is because larger diamonds have more surface area, and the impurities are more likely to be distributed throughout the crystal structure.

Diamond fluorescence is a fascinating phenomenon that can affect the appearance and value of a diamond. The fluorescence intensity can vary from faint to strong, and the color of the emitted light can also vary. A gemologist uses a special fluorescence viewer instrument to determine the fluorescence grade.

In general, diamonds with faint or medium fluorescence are not affected in value. However, diamonds with strong or very strong fluorescence may be worth slightly less than diamonds without fluorescence. Ultimately, the individual buyer’s preferences determine the value of a diamond with fluorescence.