The most valuable rubies have an orangish, pinkish, or purplish red hue, a medium-light to medium-dark tone, and saturated color. The most valuable rubies are those that have a pure color or only “slight” hues of other colors. Tone refers to the depth of color, ranging from colorless to black. Like emeralds, rubies are described as “light,” “medium-light,” “medium,” “medium-dark,” and “dark.” The most sought-after rubies have are in the medium-light to medium-dark ranges. Saturation, or color purity, refers to the degree to which the ruby is free from brown or gray hues. The most desirable gemstones, which show little gray or brown, are often described as having “vivid” or “strong” color saturation.
Unlike diamonds, rubies have no geometrically configured cut for maximum brilliance. Inclusions are generally more apparent in light- to medium-color rubies, than the darker varieties. Since rubies generally have some inclusions, look for a ruby with a darker shade, as the inclusions will be effectively hidden in these darker gems. As with emeralds, the carat weight of a ruby is not necessarily an accurate gauge of the gemstone©ˆs size.