1. Jade Colors
Color is jadeite’s most important value factor. It comes in many different colors such as lavender, red, orange, yellow etc. (Refer to Diagram 1). However, jadeite’s most desirable color is a very distinct shade of green called 'Imperial Green'. Almost transparent with a vibrant emerald-green color, this type of jade is one of the world’s most expensive gems that can cost up to millions of dollars.
Other highly valued jade varieties include 'kingfisher jade', 'apple jade', and 'moss-in-snow jade'. Apart from green jades, the next in line most valuable will be lavender (the more intense the color, the pricier). Black Jade and Orange to Reddish Jade are also popular in the market as of today.
2. Jade Transparency
Jadeite’s transparency ranges from completely opaque to semi-transparent (Refer to Diagram 2). To judge its transparency, some buyers place a thin jadeite slice on a printed page and try to read the print through it. The best jadeite is semi-transparent, meaning words would be slightly blurred if you read through it whereas, the least desirable ones are completely opaque or with cloudy patches that affect their transparency. Good transparency can sometimes compensate for lack of uniform color or low color saturation.
3. Jade Texture
Jadeite’s texture can be fine, medium, or coarse. It varies in terms of its size and hardness (Refer to Diagram 3). These categories are sometimes called old mine, relatively old mine and new mine respectively.
The most desirable ones are smooth with fine grain texture and excellent lustre, it is so appealing that it makes people want to touch them. On the other hand, the least desirable ones look "dry" with coarse grain texture and grain structure visible to the naked eye.
4. Jade Cut
The world’s main polishing centre for jadeite is China, followed by Myanmar. The finest-quality jadeite is usually cut into cabochons (a gemstone which has been shaped and polished into a rounded obverse with a flat reverse) for use in rings and other types of jewelry. When buyers judge cabochons, they consider symmetry, proportion, and thickness.
Fine-quality jadeite might also be cut into round beads, which are carefully selected and strung into strands. Color and texture are the most important factors for matching jadeite beads.
The jade bangle, first carved in China from nephrite, was introduced four thousand years. A smooth circle of bright jadeite can be highly important pieces of jewelry.
(Refer to Diagram 4 for the Types of Cut)
5. Jade Size
Jadeite size is commonly expressed in millimeters (mm). The value of cabochons, beads, and bangle bracelets rises with an increase in size, with all other quality factors being equal.
For example, slight differences in size for top-quality imperial jadeite can make large differences in value. On the other hand, With nephrite, larger sizes do not raise the value dramatically in most cases. (Refer to Diagram 5 for Example)
Referenced from GIA: