Colored Stone Color Grading Terms

The following is a list of hue, tone and saturation scales with terms and their abbreviations for describing gem color.

Guidelines for color ranges of each quality, from Excellent to Fair, are listed above the color stone price charts. The hue is abbreviated in the left column and the tone and saturation ranges are abbreviated as numbers (tone/saturation).

For example, vslbG 5/4 (very slightly bluish Green Hue, Medium Tone, Moderately Strong Saturation) is a Very Good quality color for Emeralds.

Purple P
reddish Purple rP
Red-Purple or Purple-Red RP/PR
strongly purplish Red stpR
Red R
orangy Red oR
Red-orange or Orange-Red RO/OR
reddish Orange rO
Orange O
yellowish Orange yO
orangy Yellow oY
Yellow Y
greenish Yellow gY
Yellow-Green or Green-Yellow YG/GY
strongly yellowish Green styG
yellowish Green yG
strongly yellowish Green styG
yellowish Green yG
slightly yellowish Green slyG
Green G
very slightly bluish Green vslbG
bluish Green bG
very strongly bluish Green vstbG
Green-Blue or Blue- Green GB/BG
very strongly greenish Blue vstgB
greenish Blue gB
very slightly greenish Blue vstgB
Blue B
violetish Blue vB
bluish Violet bV
Violet V
violetish Purple vP

Colored Stone