The color balance of an
emerald is the most significant characteristic of the stone.
Emeralds come in a wide range of colors, and the best quality is a combination of
color, tone and hue. The grade of color ranges in scale from poor to
The best color emerald is pure green from the color
Tone is how
dark or light a color appears. It represents the depth of color,
ranging from colorless to black. Medium dark green and deep intense
are the best one tones. However a dark green tone does not mean it
will be of the highest quality,
since it may not show brilliance or be crystallinity.
Hue describes the emerald's basic color, The most
valuable and beautiful emeralds exhibit an "intense bluish"
hue in addition to their basic green color.