Color is one of the most important factors while judging a good gemstone.
A finely cut gemstone will exhibit a good color, will have no inclusions and feature an overall symmetry and proportion.
A dark and intense color in a gemstone does not necessarily mean the stone is of high quality.
Rare gemstones are often cut for size and color isn't of prime importance. For instance, Precious stones like Sapphire and Ruby are cut for maximum weight and not their beauty; and they display streaks or an array of colors.
Medium-tone, clear, intense are some of the grading terms that define a good colored gemstone. The shade, tint or sensation of the color in a gemstone is known as hue,.Precious gemstones are known to demonstrate a pure color and will feature "minor" hues of other colors in addition to their primary color.
Look out for dominant color clarity while you evaluate hue in a gemstone. The tone in a gemstone essentially means the depth of color, varying from colorless to black. It is defined as the relative darkness or the lightness of a hue, Commonly used terms to describe a gemstone tone are "light," "medium-light," "medium," "medium-dark," and "dark." .Saturation or purity is described as the strength of a hue. It also refers to the degree to which the gem is free from brown or gray hues.
Some of the most valuable that indicate little gray or brown shares are often described as having "bright" or "strong" color saturation.