“Jade” often refer to the gemstone jadeite, a typically green member of the pyroxene mineral group. It has only been about 200 years since significant quantities of jadeite were brought into China and Japan from Myanmar. Its history is surprisingly short; what was called jade and had been used in China for 4,000 years in sculpture and other decorative arts was actually nephrite (a member of the amphibole group of minerals) and other similar minerals. The word “jade” comes from the Spanish piedra de ijada, meaning “colic stone,” because it was thought to have mystical properties to heal colic and lumbago. Jadeite is the favorite stone of the Chinese and Japanese.

Rough jadeite is opaque, with green portions being sliced out from the rough boulders. In contrast to the transparent rough of gemstones such as emerald and ruby, in which the weight of the final product can be estimated within a 30 percent range, jadeite rough is a total gamble due to its opacity. Prices vary greatly in the Hong Kong jade market, making it absolutely necessary to be able to judge quality when purchasing. It is said that polished jadeite is best judged in morning light. Conscientious dealers will avoid showing stones on rainy days, making an effort to always present the material under the same conditions in order to become a trusted source for the client.

The jadeite on the next page is one of the highest quality, with high transparency and a considerable amount of green color. This is the so-called “Imperial jade.” Historically, this level of quality has been referred to as rokan (“precious stone”) in Japan. Transparency is often responsible for the difference between beauty grade S and A; when comparing S and A in gem qualities, material that appears more transparent under incandescent light will appear slightly bluish. In Japan, this kind of material is referred to as seikan (“blue stone”). The hardness of jadeite is 6 1/2 to 7, but its toughness is higher than even diamond, making it an exceptional gemstone in this regard.