Although Jade | Jadeite has many colors; the most valued one is green. We are going to discuss how the sublte change in the green color will affect the valuation of the jade.
We have to remember color is a sensation depending on the individual receiving it and under what conditions. The same green jade looks different under different lighting conditions. (always view the jade under natural lighting!!!)
The GIA uses Munsell/HSV model (Hue Saturation Value) to describe colors. For example, a perfect sapphire would be notated as a "B 5/6"
B= stands for the hue -blue
5 is the tone
2 is the level of saturation.
Unfortunately, the jade industry never quite follows the standard set by GIA to describe the jade colors. The jade industry used a modified model to value the green jade. The image below shows 5 hues, 5 tones and 5 saturations. Since it is quite similar to the model i learned which is 6 hues, 6 tones and 6 saturations, I will still provide it for your reference, since the image is of better quality. (Sorry i do not know the source of this image).
The four factors used to describe the green jade are Hue 正，Tone 浓，Saturation 鮮 and Evenness
均.
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Hue in Green Jade
Hue is the combination of primary colors that is RGB (Red, Green and Blue). The hue of green jade will be strongly influenced by yellow and blue colors. Perfect green is the most valuable, followed by yellowish green. The lowest value will be bluish green.
- Yellowish green (60 to 65% of the jade value)
- Slightly yellowish green (90 to 95% of the jade value)
- Perfect green (100% of the jade value)
- Slightly bluish green (70 to 75% of the jade value)
- Bluish green (40% of the jade value)
- Grayish green (20% of the jade value)
Tone in Green Jade
- Extremely Dark (95 to 100%)
- Medium Dark (90 to 95%)
- Medium (70 to 80%)
- Light (50 to 60%)
- Very Light (10 to 40%)
- Colorless or white (0 to 5%)
The best grade of green jade will have a medium tone that is 70 to 80%. And this is the standard yardstick. Any green jade that has a higher tone will look black. Any green jade that has a lower tone will be colorless. And the price will be reduced accordingly. However, valuation of green jade may differ from place to place. For instance customers from Northern China and Taiwan would prefer darker tone; while Singaporeans prefer a lighter jade color. Hongkongers' preference is between these two. On the other hand, older people will prefer darker tone while the youngsters like lighter tone. An important point to note is that the tickness of the jade will influence the tone.
Saturation in Green Jade
Saturation is the purity or intensity of the hue. The scale goes from 1 to 6. The lowest grade means the hue looks grayish; and the highest grade means pure in its hue.
1. Grayish (0 to 5%)
2. Slightly grayish (10 to 40%)
3. Very slightly grayish (50 to 60%)
4. Moderately Strong (70% to 80% without any gray)
5. Strong (90 to 95%)
6. Vivid (95%)
Evenness in Green Jade
Uneven color is a special feature of Jade, since it is formed by microcrystalline. We can check the evenness in green jade from the top, bottom and side of the jade stone.
The more even the green color is, the more valueable the jade is.
If a jade bangle has 20% of green color, concentration on an area is more valueable than it is spreaded all over the whole bangle.The six grades of evenness is as follows:
- Very Even (95 to 100% of the jade has green color)
- Even (80 to 95% of the jade has green color)
- Moderately Even (60 to 70% of the jade has green color)
- Moderately Uneven (40 to 50% of the jade has green color)
- Uneven (25 to 30% of the jade has green color)
- Very Uneven (10to 15% of the jade has green color)