Diamond possesses a quality called fluorescence.
This criterion is part of the evaluation and assessment of a diamond.
Fluorescence, which is also call photo-luminescence is activated by UV light.
The glow comes about because of a chemical called boron in the diamond, which is usually found in small quantity within the diamond.
Fluorescence is one area that gemologists used to identify and separate diamonds from their look-alikes.
When under a UV lamp, diamond will glow in blue.
This will not happen for crystals such as moissannites and cubic zirconia.
In fact, most diamonds fluorescent under natural light as natural light contains small amount of UV frequencies light.
A blue-white diamond refers to a diamond with some fluorescence.
The blue refers to the diamond fluorescence, while the white indicates the overall color of the diamond.
Colorless diamonds are becoming more and more expensive as anything that have color grades D (flawless) to G are rare and cost a bomb.
Diamonds with grade H or higher have some gradations in the stone, so a bit of blue florescence can offset the yellowish tone.
This in fact can increase the stone's value and attractiveness.
When buying such a diamond, remember to examine it in various light conditions, such as sunlight, fluorescent light and also a jeweler's black light.
Some blue-white diamonds can become hazy in the daylight, while brilliant in other light conditions.
There are a few grades to indicate the amount of blue in blue-white diamonds.
The grades are - None, Faint, Medium, Medium blue, Strong, Strong Blue and Intense Blue.
Unless you are buying a yellow diamond, it is not advice to buy a white diamond with a yellow fluorescence or any other color.
A colored diamond with a similar fluorescence will enhance and intensify that color, but not really so for colorless diamond.