Cultural Background.

Jade has long since held a special place in Chinese culture. In addition to its historical significance and aesthetic appeal, Jade continues to fascinate people because it signifies the Confucian virtues and beliefs engrained in Chinese tradition. The symbolic values of Jade are most succinctly and poetically expressed by Confucius when he compares the qualities of Jade to the virtues of a true junzi:

Its soft, smooth luster suggests charity of heart;
Its density connotes wisdom;
Its rigid yet gentle texture represents integrity;
Its lucidity reveals equally its excellences and flaws, exemplifying honour;
Its translucency provides luminosity, demonstrating tolerance and generosity;
When struck, it resonates a clear note, long drawn out, fading gradually away, connoting serenity.

The unique colour and texture of Jade make it an ideal element for sculpture. Jade art is often designed and crafted to complement the natural characteristic of the material so that nature and art cohere. In light of Jade's strong cultural background, our contemporary approach to archaic Jade should place science alongside history to achieve a heightened awareness of its significance.

Jade ranges in color from pure white to black and pale yellow to dark green. It has a very creamy appearance and has always been considered more valuable in Chinese society than any other substance. Jadeite is very similar to Jade in appearance, however it is a completely different substance. It is harder, more translucent and has a crystalline structure. Jadeite is found in all the colors of Jade, but also in shades of purple and blue. Most of the Jadeite used in China comes from Burma.

A Little History..

Jades are extremely hard stones (6.5 to 7.0). They were shaped and carved using ropes and bamboo with grains of sand. The piece was coated with sand which was rubbed back and forth with the rope or bamboo to slowly wear away the stone. A single piece could take months to produce.

The traditional Jade of China was Nephrite. It was worked in that country as early as the Late Neolithic period (ca. 3000-1500 B.C.). Apparently, all the Nephrite rough was imported from sources outside China, for even in modern times there seems to be no substantiated Chinese deposits. It is believed that the Chinese sources for Nephrite were located, in olden times, in East Turkistan, from which boulders were transported for many centuries over most difficult transcontinental routes to their final destination in China. During the past century, however, much of the rough destined for China came from New Zealand, Siberia and Canada.

Jadeite was introduced to Chinese artisans only about the middle of the 18th century, during the reign of the emperor Ch'ien-lung (1736-1795). It is said that the Chinese knew of the Jadeite of Burma since the 13th century of the Christian era; but some five hundred years elapsed before any Jadeite Jade reached China and was worked on anything like a large scale. This was due not so much to transportation difficulties as it was to a long-lasting "cold war" and political conditions, generally. The Chinese and Burmese were definitely not good trading partners. Even when it was brought to China, Burma Jadeite took almost a century to become accepted as a valuable stone; and it was probably due to the old empress dowager, Tz'u Hsi, who loved its bright, vivid colours, that it finally reached pre-eminence as the Imperial Stone or most precious thing, in China. It is generally believed that no art objects were created in China from Jadeite much prior to that time. Indeed, it is fairly safe to date intricately carved vases and the like fashioned in Jadeite Jade to the various periods after about 1780 A.D.

It was the recognition of the toughness of Nephrite that probably induced the world's ancient peoples to utilize it for the making of weapons, tools, bowls, vases and, as civilization advanced, carved images of flora and fauna of both secular and religious significance.

The art of Jade carving has been in existence in China since 3500 BC. The most famous Jade works were produced in Suzhou, which still produces some of the finest Jade and Stone carvings in the world. Nephrite Jade used by the Chinese came from East Turkistan. Throughout history, China has gained and lost control of that region which had greatly affected the supply and quality available to the craftsmen.
During the periods of low supply, smaller pieces were produced. Craftsmen were required to produce Snuff Bottles using very low quality Jade, much of which had off-color inclusions. These inclusions were frequently worked into the design of the piece. Many of these low-grade pieces are extremely valuable today.

Whilst deposits of gem quality Nephrite are widespread throughout the world, there is only one source of any importance for the varieties of Jadeite used in modern jewellery, and for carvings and art objects. That source is located at My-it-ky-ina in the Shan mountain district of Upper Burma, about 100 to 125 km west of the town of Mogaung, which is the sorting and storage centre.

Chemistry and Physics.

The name Jade includes both Nephrite and Jadeite. Taken separately, Nephrite is a silicate of calcium and magnesium (with some iron in the ferrous state) and belongs to the amphibole group. Jadeite, the "companion" mineral, is a silicate of sodium and aluminum belonging to a group of rock-forming minerals known as pyroxenes. Both are inosilicates characterized by sinews or chains of silica tetrahedra. These may be simple oxygen-linked strings or complex double chains latterly bonded to various types of cations, that is, positively charged atoms, that produce differing mineral species such as diopside, enstatite, Jadeite, spodumene and the like. The pyroxenes have simple, single chains whilst double-chain structures are characteristic of the amphiboles, such as Nephrite, hornblende, tremolite, actinolite, etc.

It should also be noted that pyroxenes are anhydrous, whilst amphiboles contain water and will give off water vapour or steam when heated in a closed test-tube. Also of interest is the fact that the amphiboles tend to be fibrous, acicular or elongated in habit. Both Jadeite and Nephrite are monoclinic.

Nephrite.
The best green Nephrite takes on almost a mirror finish when polished with diamond in the modern manner. It came from British Columbia during the late 1950's and early 1960's, and is still being mined there at several localities. Its hardness (about 6.5) is very close to that of Jadeite and the colour is a deep apple green.

The fact that Nephrite from other localities does not generally accept an even polish is due to (1) the presence of other minerals – associated or as inclusions – and/or (2) variations in the felting of the crystals that comprise the variety of Jade we know as Nephrite. Some sections have been shown to be more densely matted than others, hence take a higher polish than do adjoining less-tightly felted areas. Additionally, it may be said that the matted structure of Nephrite Jade makes it one of the toughest but certainly not the hardest mineral known.

Jadeite Jade
Jadeite is somewhat less tough but slightly harder than Nephrite. It has a fine granular structure of interlocking crystals that may vary slightly in hardness. This gives rise to a subtly dimpled surface when the material is cut and polished. In late years, however, the use of diamond in the polishing process has made the dimpling much less apparent. It has also resulted in a higher polish, making the age of the piece more readily recognized as modern or re-finished.

Jadeite, with a hardness of 7 on the Mohs' scale of relative hardness, occurs in white, grey, pale blue, pale lavender, yellow, mutton-fat cream, orange, brown, burnt-sienna red, black and, of course, green. The greens are most favoured in the Western world and vary greatly in saturation and hue, from the palest of greens to a deep translucent emerald hue. The Chinese also favour an even darker translucent green colour, but this has the tendency to appear blackish in artificial light. The rare fancy colours are also gaining world-wide attention for their rarity and innate beauty, especially when they are set next to the brighter green shades.

Although green Jadeite and emerald both owe their colour to chromium, Lavender Jadeite is frequently dyed. Anything but a pale shade is immediately suspect. Dyed lavender Jade shows orange under LW UV light.
Most Jadeite regardless of colour will remain suspended or very slowly sink in methylene iodide (di-iodomethane) that has a density of about 3.32-3.33 at normal room temperature.