Fluorescence is another characteristic of the diamond that should be considered before buying. It refers to the blue glow, which is emitted by some diamonds under ultraviolet light. This glow can vary from low, to moderate, to very bright blue. Fluorescence is a complicated characteristic as it can either decrease or increase the worth of a diamond. Fluorescence is not that beneficial for colorless diamonds graded D, E or F. However, for stones that have yellowish tinge, such as J, strong or medium fluorescence helps in making it appear white. Consider all the above stated factors and have a happy diamond shopping experience.