signifies qualities such as beauty, purity, splendor, and the highest honors, rather than a particular stone. Yü does not pertain to jadeite. The Chinese call this Burmese stone fei t'sui after the kingfisher bird which sports a brilliant green plumage. Thus it can be readily seen that the old texts are often misleading.
Jade has been found in other parts of the world. In the United States it is native to Wyoming and California. Large deposits are also found in western Canada and Taiwan. The Maori people of New-Zealand, the Eskimos of Alaska, the Aztecs and Mayans of Central America all carved jade which they found in situ. The Chinese, however, who had to open trade routes and keep the importation of jade rough flowing over thousands of miles via water and beast of burden not only recognized the intrinsic beauty of the stone but possessed the artistic genius to develop this medium from its early archaic form to the simple refinement of the Ming dynasty, on through the highly decorative Ch'ing dynasty. Of course, it is characteristic of human nature to seek that which is difficult to acquire, to conquer that which offers the most resistance, to assume the task which poses the greatest challenge. The Chinese obviously set out to prove themselves capable of not only mastering the actual cutting procedures, but of creating magnificent works of art which bear witness to their artistic ingenuity.
Jadeitc and Nephrite: Their Mineral Properties
Before we enter upon the study of the jade carvings themselves, it is well to know a few basic facts about material, workmanship, and dating. Nephrite belongs to the amphibole group of minerals, and jadeite is a member of the pyroxene family. A detailed study of the chemical composition of each can be found in Hansford's book, Chinese Jade Carving [21]. For our purposes it is sufficient to quote Hardinge, "The wide colour range of the jade-stones is due to the presence, usually in minute quantities, of various metallic oxides, especially those of iron, chromium and manganese" [23]. The color variations are innumerable. Nephrite ranges in color from pale green to moss to spinach, white, gray-white, mutton fat (yellow-white), deep gray, brown, red (rust brown), to black, yellow and combinations thereof. Siberian nephrite is a medium green color flecked with tiny black spots and is often translucent.
Jadeite is generally of purer or more vivid coloring than nephrite due to the presence of chromium, the same element that gives emeralds their rich green color. Jade-ite is snow white, emerald green, lavender, blue, and mixtures of these colors. As mentioned previously, a piece of green-and-white jadeite is often called Jei t'sui. The brilliance of fine jadeite material can be breathtaking! Some years ago, I visited the California home of the late Admiral Yannopoulos, an avid jade collector. Enclosed in a cabinet stood an emerald green, translucent jade incense burner, approximately 9 inches tall by 7½ inches wide, of almost uniform color consistency. The vessel was free of decoration other than the carved loosering handles and dragon finial topping the cover, and it bore a high polish, the extreme simplicity of design permitting full appreciation of the material itself. Such pieces are rare, as pure green jadeite is usually found in small specimens suitable for jewelry, seals, palm pieces, etc.
While humerous texts and catalogues refer to "pink" jade, the description is an erroneous one. In every case where the author has come across examples of this color, both in and out of museum collections, tests have proven the material to be other than jade. Sometimes a jade carving is painted on the inside so that a rosy glow is reflected through the translucent material. More often, however, the "pink" jade carving will turn out to be chalcedony quartz, rose quartz, pink garnet, or thulite. Mr. Robert Crowningshield, Director of the Gemological Institute of America, states that in twenty-five years of examining minerals he has never found a carving, geode, or even the tiniest specimen of "pink" jade. We must conclude then that pink jade is non-existent; all statements to the contrary are either honest mistakes or extravagant fancy.
In addition to the color differences between nephrite and jadeite we should consider the matter of surface quality, which further distinguishes the two materials from one another. Nephrite, when polished, takes on a waxy or soapy appearance. Jadeite gleams with a fine gloss. Hansford describes the "lustre of nephrite [as being] oily rather than vitreous and that of jadeite the reverse" [21]. True, the new nephrite carvings made in Peking today sport a high polish in comparison to the older examples. This is probably due, however, to an improvement in the polishing substances used. Nevertheless, jadeite subjected to the same carving and buffing methods assumes a brighter sheen.
These are the easily visible differences between neph-rite and jadeite. What about some of the invisible elements which differentiate the two? Hardness is an important factor. Friedrich Mohs' scale is used to determine the hardness of minerals. Nephrite measures 6.50, while jade-ite ranks 6.50 to 7 on this scale of 10. The diamond is the hardest stone ranking at 10. So there is a small difference in the hardness of nephrite and jadeite.
Next let us examine the actual consistency of these materials. Though a bit softer than jadeite, nephrite is fibrous, rendering it a little tougher than its counterpart and consequently more resistant to the cutting tools. Jadeite has a crystalline composition, that is, its structure is made up of crystals. Mr. Crowningshield tells of having seen a shattered jadeite specimen, from the center of which a single prism had fallen out intact. Thus we can understand why both nephrite and jadeite offer individual problems which challenge the skill and capacity of the craftsman.
How to Verify Genuine Jade
The expert can usually determine whether a carving is nephrite or jadeite or neither. He is aware of color, polish, and mineral composition. But even the experienced are fooled occasionally. There are many stones which imitate jade. Why care if the carving is jade or not as long as it looks as good? Why is a carving more valuable because it is jade rather than serpentine (sometimes called onion jade or new jade), soapstone, green quartz, green garnet, chrysophrase, smithsonite, or chalcedony? The answer is a multiple one. First of all, fine jade rough is available in very limited quantities. Secondly, other minerals which bear a strong resemblance to jade generally do not exhibit the beautiful color properties of nephrite and jadeite. Last but not least, jade is more durable than its imitators. As usual, there is no satisfactory substitute for the real thing.
Minerologists have devised various tests to establish whether or not a particular example is genuine jade. The simplest method is to attempt to scratch the surface of the stone with a sharp blade. Theoretically, if it scratches it is not real jade. However, certain quartzes and types of serpentine are virtually as hard as jade and will not yield to the knife blade or razor edge. Hence the scratch test is not conclusive. Recently, further difficulty has arisen with the advent of stainless steel razor blades. These harder instruments will bite into genuine jade material, so this test is indecisive.
Nephrite has a specific gravity of from 2.90 to 3.20 and jadeite measures 3.20 to 3.50. Small carvings such as snuff bottles can be immersed in a heavy liquid such as bromoform, the density of which will permit the false jade to float, the heavier genuine jade to sink. This method is not recommended for pieces which have painted decoration or are treated (tinted) in any way, as the chemical liquid is likely to remove the color.
Sir Charles Hardinge notes that experiments were done by the Freer Gallery in submitting jadeite and nephrite to extreme heat. At a temperature of 1,025° centigrade, jadeite liquified to a colorless glass and dried to a distorted shape, while nephrite changed to a yellowish, opaque substance resembling calcined bone [23]. The latter case brings to mind certain examples of jade carving which are thought to have changed color due to exposure to fire or extreme heat (Plate 10).
Obviously the collector, considering what may turn out to be the most prized addition to his cabinet, is not desirous of subjecting it to scratches, drowning, burning, and other means of mutilation! The researchers may keep their share of adventure and we are most grateful for their findings, but it is suggested that when in doubt you take the article to the nearest gemological laboratory such as the Gemological Institute of America which has branches in New York City and Los Angeles. There they will place the piece under the surveillance of scientific apparatus such as the spectroscope and the refractometer. These machines measure the optical
