Diamonds have many unique properties, including natural blue fluorescence under any source of ultraviolet light.  Most diamonds have some degree of fluorescence under natural light, which contains small amounts of UV frequencies.

Fluorescence influences the beauty or value of a diamond based on the color grade you are buying.  Some within the industry argue that fluorescence in any amount does not impact the face up appearance of a diamond, except possibly those with extreme fluorescence.  However, from my experience, it does affect the overall beauty & sparkle of a diamond.  In some cases it enhances and in other cases it detracts from the beauty & value of a diamond.

If a diamond has a color grade of J to M, a moderate amount of fluorescence will actually make a diamond more attractive to most people. Slight to moderate or even strong blue fluorescence in a stone with these color grades actually helps cancel some of the yellow and makes it looks whiter. However, we do not sell diamonds with a Color grade lower than 'H".  We prefer "white" diamonds.

In a diamond with very high color (such as a D to H grade), fluorescence interferes with the flow of light and makes the diamond appear a little oily or murky. We avoid these diamonds.

In Fancy Colored Diamonds, such as X, Y, or Z color grade, strong Fluorescence drastically enhances the diamonds color and overall beauty.

Colorless Premium diamonds have no Fluourescence, while Colorless "Discount" diamonds tend to have some level of Flourescence.

Our diamonds contain No Fluorescence, because side by side, diamonds with no Fluorescence are just simply more beautiful.