Jadeite quality factors
Jade consists of two different materials, jadeite and nephrite, and is a term used to describe both materials. However, the physical properties of jadeite and nephrite are very different and thus, identification of quality in the two materials is also a very different exercise. Jadeite, in particular, has relatively clear discerning factors to look at in identifying its quality. One of the important factors affecting the quality of a jadeite would be translucency.
Translucency and Why It Matters
Translucency is a subset of transparency as a google search of its definition explains. It is the amount of light that can pass through an object. The more light can pass through, the more translucent the object is. In jadeite, the higher the translucency of a jadeite piece, the more valuable it is. Translucency is also a factor of how thin a jadeite piece is. As such, thinner pieces of jadeite which are clear and translucent, are valuable, however, they will pale in comparison to a thicker piece with similar translucency. The differences in prices are clearly evident as well. A completely clean and translucent jadeite piece of a considerable thickness will most likely be far more expensive than a thinner piece.
In grading terms, laboratory reports from Nanyang Gemological Institute (NGI), which certify jade pieces from All About Jade, classify colourless jadeite pieces broadly into 2 categories if they are translucent enough. The first being icy jadeite and this is a qualification of jadeite if it is of a high level of translucency. The second category is only offered to jadeite pieces that are extremely clear and translucent, and this is the glassy variety of jadeite. Both classifications are given only after laboratory testing of how light passes through the jadeite pieces. For non-colourless jadeites, the reports will indicate translucency in the remarks section of the report and similarly, only jadeite pieces with high levels of translucency are given these special remarks.
Identification of the translucency of a jadeite piece is easy from a laboratory report. However, in cases where a jadeite piece, like a bangle, is large and has more material, laboratory reports can only indicate so much. Translucency in jadeite is rare. Only a very small percentage of jadeite pieces in the market have decent levels of translucency and their rarity directly correlates to their prices. In many cases, even if a portion of a jadeite bangle is translucent, the bangle will be worth much more than a more opaque piece of a similar colour.