The number one driver of colored gemstones value is in fact the color.
Gemstone color has three factors:
- Hue indicates the basic color; gemstones often contain primary and secondary hues
- Saturation indicates how intense or “clean” the color is. Desaturated colors are diluted or modified with different grades of grey or brown.
- Tone indicates how light or dark a stone is: add black (dark) or add white (light)
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| Blue, high saturation, medium tone | Blue-Green, slightly desaturated, dark tone | Blue, medium saturation, light tone |
Generally preferred color is pure and intense (high saturation) and is of medium tone (no black, no white). Moving towards violet hues tends to increase the value (blue with violet, red with violet) while moving away from violet tends to decrease the value in relative terms (red-orange, blue-green).