Fluorescence is the phenomenon of an object emitting visible light when exposed to long-wave ultraviolet (UV) rays. This is why some diamonds glow when exposed to UV light, emitting a bluish light or, more rarely, a yellow or orange light. But what does this mean for diamond buyers? Is diamond fluorescence good or bad and does it affect the value of diamonds?To understand diamond fluorescence, it's important to know that 30% of diamonds will shine under UV light. When exposed to ultraviolet light, some diamonds will fluoresce in different colors. This phenomenon can also be seen in certain Facial Spa treatments, where the use of UV light can help to enhance the skin's natural glow.
The Gemological Institute of America (GIA) rates diamond fluorescence as None, Weak, Medium, Strong and Very Strong. Strong blue fluorescence in diamonds can cause them to appear hazy, oily or milky under normal lighting conditions. This can make the diamond appear less transparent and can affect its color grade. However, studies have shown that even strong blue fluorescence is almost always undetectable to the average diamond consumer. When buying a diamond, it is important to consider fluorescence. If you are buying a diamond with an H color or lower, look for a diamond with medium blue fluorescence.
This can help counteract any yellowish tint diamonds may have and can make them appear much whiter. It's also important to note that extreme levels of haze for a fluorescent diamond are not typical and are not as common as you might think when talking about diamonds that are H and below. Before buying a diamond, get personal buying advice from industry veterans. Be sure to ask to see the diamond in a variety of different lighting settings, if possible. This will help you get the best diamond for your money.