How is gemstone color described and evaluated?
Color is easily perceived by our sense of vision, but very difficult to describe by word. Gemstone dealers use various systems to describe color. In one system the “color world” is a three dimensional structure consisting of hue (spectral colors such as red, yellow, green), tone (the impression of lightness or darkness), and saturation (the impression of strength or purity). A fine Columbian emerald might be described as: medium (Tone), strong (Saturation), very slightly bluish green (Hue). Verbal or numeric systems for color description are generally of use only to those in the trade. Gemstone dealers can use expensive spectrophotometers or inexpensive color reference sets to accuarately grade gemstone color. Trade publications are available that correlate gemstone color and price. The gemstone consumer can begin to appreciate the important correlation between price and gemstone color by visiting jewelery stores, gem shows, or various internet sites to make price comparisons.
