Although the ancient Chinese felt a close affinity with jade they did not define strictly what jade actually was.

 The ancient definition was that any beautiful stone.

In the epistemology dictionary written by Xu Shen in the 1^st. Century AD jade is describe as any stone that has the five virtues.

 The five traditional Chinese virtues are benevolence, righteousness, wisdom, courage, and purity. When we speak about jade the five correspondences occur luster; uniformity, pitch, hardness, and ease into being cut at right angles.

 Many kinds of stones can be called jade by this definition. So many Chinese characters for different kinds of stone contain a composite that symbolizes jade.

 After years of scholarly debate many stones which were previously thought to be jade had been reclassified and been given there own special name.

 For instance the ancient fine jade has been renamed carnelian.

 Ancient pearl jade is now more accurately named Shui Yu.

 And the water jade of old is simply called crystal.

 Modern mineralogist emphasis the scientific definition of jade and divided the precious stone into two categories Soft and hard. Both the soft and hard jade is in a silicate.

 Soft jade is called nephrite

 While hard jade is called jadeite

 The crystal structural of jadeite is not readily apparent it is distinguished from nephrite by its glass like luster.

 Both types of jade come in silicic, acid form and there are white varieties of both jadeite and nephrite. One kind of nephrite is called mutton fat jade for it soft white glow which is especially popular with jade concourse.

 On MOE scale of hardness diamonds rate ten jade fells between a five, six or seven and nephrites fall between a 6.5

 Many jade artifacts created during China five thousand year long history has survived down threw the present day. Most of these articles were carved form the softer relatively nephrite.

 The harder jadeite became common only after the end of the 18^th. Century. The jadeite that Chinese are most familiar with is Hui Shi.

 During the Han dynasty some two thousand years ago the words Fei and Cui refereed to a kind of bird that lived in what is now Quang-xi Province. The Fei denoted red feathers of a bird while the word Cui denoted the green feathers.  

By the 11-century AD the two words were being used as a kind of a name for an emerald green jade but is now classified as jadeite.

 Noting that most of the jades carving that have survived to present are either jadeite or nephrite. Some scholars have turned these two types as real jade.

 However recent archaeological discoveries revile that many of the ancient cravens are not jadeite or nephrite.

 So those who study Chinese jade art cannot rely on the strike definition provided by mineralogist. Many of the semi precious stone that have the five virtues were used in place of jadeite and nephrite but were still called jade.

 In fact several jade substitutes are commercially available today, South African, Australian jade, and Philippine Jade to name a few.

 Through out their long history Chinese have many jade substitutes by two thousand BC Chinese have been using Nan Yang jade. And a mere two thousand years later they were creating beautiful objects out of Azures field jade.

 A famous Chinese poet form the Tong dynasty Lee Shang-yin once wrote the line "Azures field beneath the warming sun the jade unites in pools of smoke' to describe his pleasure at viewing blue mountain cliffs illuminating by the rising sun.

 In years past jade was divided into two types living jades and classic jades.

 Classic jades were any of the ancients jade's artifacts that had once been buried in the earth. Living jade are pieces of art works that had never been buried.

 Livings jade were passed down form generation to generation. Classic jade included jade artifacts unearth during excavation of ancient tombs. The older the jade the more valuable it was considered to be.

 Recently Chinese have begun to distinguish between ancient and modern jade. 

During Chinas last dynasty any jade carved prior to 1684 was considered ancient.

 Nowadays the dividing lines between ancient and modern lies at the beginning of the twentieth century any jade carved after 1912 and the founding of the Republic of China is modern.

 Ancient jade is generally heavier than modern jade but weather ancient or modern jade is a mineral rich in enchantment and lore.