In most cases the term white diamonds will refer / applied to the colourless diamonds also called clear diamonds niche. Their color chart range starts at letter D which consider the pureist color hue (crystal clear color very transparent just like a drop of water) and ends at Z which contains tints of Yellow and Brown Clear diamonds do not contain any White color in them. On the other hand Natural fancy White diamonds are not part of the colorless diamonds group because they are White. White does not appear in the color spectrum since white is the sum of all colors.
The reason for the actual White color is due to the presence of the sub-microscopic inclusions scatter light passing through the diamond and by that giving it a translucent milky White face up appearance. White diamonds are also sometimes describe as Opalescent because of the flashes of color can be seen while viewing the diamond face up. White Diamonds are in-frequently submitted to GIA however the ones that GIA has examined were unearthed from the Panna mine in India. Natural White diamond are usually very rich in hydrogen (pure type IaB). White diamonds can have Yellowish, Grayish, Blueish and Brownish appearance.