Material of Ancient Chinese Jade Stones

The word "Jade'' is English translation for the Chinese word `Yu'. `Yu' is used to describe grey, green, brown and black hardstones although the English term is used to describe a very specific stone type.

Jade is stone made from two minerals, nephrite and jadeite. Jadeite, which was originally discovered in Burma, was not known in China before the eighteenth century. Nephrite is now excavated in Xinjiang Region (Chinese Central Asia) but in ancient times, may have been extracted from other areas. Both nephrite and jadeite are particularly hard to extract and refine.

Both jadeite and nephrite are formed from crystallite rocks, which means that their crystals have been crushed together over many millions of years to make a matted or felted form. They do not split or fracture easily and the stones must be ground with hard, abrasive sand.

While most of the pieces illustrated are made of nephrite, a few are made from serpentine or other softer stones. Nephrite is found in the cracks of non-precious rocks. The non-precious rocks usually crack and split as a result of being weathered over a long period of time. The jade segments then break off and are washed down into the rivers. The jade is then collected and, while the result that small and large boulders of jade are often washed down in rivers. These pebbles or boulders are harvested and cut into slices with a cord. Later they are shaped using abrasive sand.

The fact that most jade carvings are shaped into pleasing or aesthetic shapes give the impression that they were easy to produce. However it belies the many ardous hours and heavy labour used to carve such beauty. In fact, even one piece (such as those illustrated) may have taken several months to carve. Given the huge effort required to produce a single piece, it is nevertheless surprising that Chinese jade is still being carved and produced on such a large scale.