A diamond's color is measured against a series of masterstones. While most diamonds are colorless to slightly yellowish, the most sought after diamonds are in the colorless or near colorless range. A "D" graded diamond is at the top of this grading range. Many and most beautiful diamonds are found from this letter grade through letter "H" on a scale that runs to the industrial type diamonds the furthest down the scale in the "Z" range.
Diamond color occurs naturally in a wonderful array of colors from the champagnes or light brown, to striking yellow, pink, purple. blue and red.
These colors are known as "fancy" and generally are available by special order.
Certain diamonds contain flourescence which reacts in "black light." This flourescence can range from nil to strong. This characteristic of a diamond is also measured and graded.