Paradoxically enough, the more colorless the diamond, the greater is its rarity and value. Although many diamonds may appear colorless to the untrained eye, the majority contain very slight traces of yellow or brown. Paradoxically as well--"Color" in diamond grading refers, in fact, to the degree of colorlessness...
Color quality is critical because a diamond value increases dramatically the more colorless it is. Color determination consists of comparison with Master-Color diamonds under daylight conditions by the grading laboratory.
A single increase in a diamonds color grade can hike a diamond's value by thousands of dollars depending on the size and clarity grade combinations, and, in most cases, will have more effect on the diamond price than one clarity grade difference. Diamond colors are graded from the letter «D» (Colorless) to «Z» (prominent hue); The letters «A» to «C» are reserved for other scales and uses.
A hardly noticeable tint of yellow is added with each letter progression. Still, up to the letters «G» and «H», those minute traces of yellow are hardly noticeable by observers other than professionals.
The most popular levels of hue traces in diamonds are described in the diamond trade. traditionally as follows:
«Colorless» is a color distinction grade for diamonds, designated by the letters «D», «E» and «F», whereby diamonds graded «D» have no trace of any color whatsoever, and «E» and «F» have the minutest of such traces, discernable only by experts or trained eyes (the letters A, B and C are reserved to particular actual colors and purposes).
«Near Colorless» is a color distinction grade for diamonds, designated by the letters «G», «H», «I» and «J», whereby diamonds graded «G» possess traces of color (usually palest of yellow) discernable by experts and very trained eye, «H» graded diamonds may show the faintest trace of color when placed next to other diamond of two or more higher grades of color, and «I» and «J» grades show traces of color to the observant examiner.
«Slightly Tinted» is a color distinction grade for diamonds, designated by the letters «K», «L» and «M», whereby those diamonds will display increasingly discernable levels of traces of faint yellowish coloration.
What color grades are acceptable and what are the best?
The issue of acceptable level of color is personal. After all, some buyers would deliberately opt for heavily yellow tint diamonds beyond the «Q», «R» and «S» levels, or even deliberate yellow colored diamond. However, for those who wish to buy a Diamond of no color, the «D» to «F» range would offer diamonds of their desired appearance, while the range of «G» and «H» offers great diamonds of hardly noticeable tint.
A word about Fluorescence
Diamond fluorescence is the physical property of showing a glow under a source of light very rich in ultra-violet rays. Under a very concentrated source of such light, very similar to «black Light» (sometimes called «disco light») a fluorescing diamond will show various levels of turquoise color (if its fluorescence is blue. In rare cases it could be yellow. The color is usually marked on the grading report). The phenomenon manifests itself only under such conditions and is otherwise impossible to detect. Diamonds that possess fluorescence offer an excellent value as their price is reduced, as very few amongst very-strongly-fluorescing diamonds may have also a «haze» interfering with their return of light. Notice, again, that this is restricted to few amongst the very-strong fluorescing diamond, and does not manifest in other levels of fluorescence. The terminology used to describe fluorescence, and, depending on the grading laboratory, uses terms such as «Faint» (or, «Negligible»), «Weak», «Medium» (or «Moderate»), «Strong» (or, «Intense»), «very Strong» etc. In the opinion of most specialists and institutions such as the GIA, and to most trained, and certainly untrained eyes, a diamond's Fluorescence has no detrimental effect on its performance, hence the great value for the reduced price (in the past, in fact, those diamonds were sold for a premium as possessing mystical properties).
