1902 Encyclopedia > Jade
JADE, a name popularly applied to several distinct ornamental stones, but restricted scientifically to a definite mineral species known as nephrite. The term nephrite, from the kidney, refers to the reputed value of the mineral in renal diseases, whence it was formerly known as Lapis nephriticus. Probably the word jade is a corruption of the Spanish hijada, since this mineral is one of the stones which were known to the Spanish conquerors of Mexico and Peru under the name piedra de hijada, or "stone of the loins" a name which first appears in the writings of Monardes, in 1565, as peidra de la yjada. So numerous have been the names applied to this mineral in various parts of the world, and at different times, that Professor Fischer has collected nearly one hundred and fifty synonyms of jade.
True jade, or nephrite, is a native silicate of calcium and magnesium, which may be regarded as a compact or crypto-crystalline variety of hornblende, and may be referred either to actinolite or to tremolite, according as its color tends to green or to white. It never exhibits crystalline form of distinct cleavage; but, according to recent observers who have visited the old quarries in Turkstan, and have seen the mineral in situ, traces of cleavage may occasionally be observed; usually, however, the substance breaks with a splintery fracture. The specfic gravity of jade varies from 2-91 to 3-6, and offers one of the readiest means of distinguishing between this mineral and others with which it is likely to be confounded. Most specimens of jade are scratched by flint or quartz, their hardness being about 6.5; but, while the hardness is not excessive, the mineral is remarkable for its toughness. It is notable that Hermann von Schlagintweit, who inspected the quarries in the Kara-kash valley, found that the hardness of the stone when freshly broken was considerably less than assumed by it after a short exposure. The color of jade is subject to great diversity, - some varieties presenting almost every shade of green, while others are yellowish, grey, or even white.
So far as is at present known, no true jade has ever been detected in situ in Europe. A loose block has been found at Schwemsal near Leipsic, and the mineral is said to occur in the drift at Potsdam near Berlin. Corsica and Turkey have also been recorded as jade localities, but probably on insufficient grounds.
It is by the Chinese that jade has always been most highly prized, and, notwithstanding its intractability, most elaborated carved. To the Chinese it is known under the name of yu or yu-chi (yu-stone). Much of the Chinese jade was formerly obtained from quarries in the Kuen-lun mountains, on the sides of the Kara-kash valley, in Turkestan. These ancient workings were visited and described a few years ago by H.v. Schlagintweit, by Dr Stolicka, and by Dr Cayley. The mineral is found in nests and veins running through schistose and gneissose rocks. It is probable that jade occurs throughout the Kuen-lun range, and that a rich site exists to the south of Khotan. The Khotan jade has been known to the Chinese for upwards of two husband years. In Turkestan the jade is known as yashm or yeshm, a word which appears in Arabic as yeshb, and is said to be cognate with or jasper. Indeed, by early mineralogists the jade was often described as jaspis viridis.
Fine boulders of dark green jade have been found by M. Alibert in the neighborhood of his graphite mine near Batougol in Siberia.
New Zealand is one of the most famous localities for jade, and the stone is highly prized by the natives, who work it, with great labor, into amulets, axe-heads, and various other objects. Among these objects may be mentioned the peculiar club-like implement known as the mere or pattoo-pattoo, and the hideous breast ornament termed hei tiki. By the Maories jade is known as punamu or "green-stone," and the occurrence of this mineral along the western coast of the south island has led to the name Tewahi punamu, or "the place of the green-stone," being applied to this district.
Jade also occurs in New Caledonia and in some of the smaller Pacific islands. in consequence of its use by the South Sea islanders as a material for making axe-heads, it is often known to German mineralogists as Beilstein or "axe-stone."
Under the name of "oceanic jade," M. Damour has described a fibrous variety found in New Caledonia and in the Marquesas Islands, having a specific gravity of 3.18, and differing from ordinary nephrite in the proportion of lime and magnesia which it contains. If this oceanic jade be recognized as a distinct variety, the ordinary nephrite may be distinguished as "oriental jade."
Although it was from America that the original jade, or "spleen-stone," was introduced into Europe, it is curious that few, if any, American localities for this mineral are recorded in modern works on mineralogy. Dr Dawson has, however, noted its occurrence in British Columbia. At the time of the Spanish conquest of America, amulets in jade or in some jade-like mineral were highly venerated throughout Mexico, Central America, and Peru. It has been supposed by Mr. E.G. Squier that jade was one of the green stones so greatly prized by the ancient Mexicans under the name of chalchihuitl. The "Amazon stone," which has sometimes been regarded as jade, is a green variety of microcline-felspar; while the "Bowenite" from Smithfield in Rhode Island, which was at one time supposed to be nephrite, is found to be a variety of serpentine of unusual hardness. Serpentine is also used as a substitute for jade in some of the common objects imported from China.
While true jade has not hitherto been found in situ in Europe, it is a very suggestive fact that Neolithic celts and scrapers have been found among the relics of several of the ancient pile-dwellings in the lakes of Switzerland. The principal localities have been the stations of Luscherz and Schaffis on the Lake of Bienne (Biel), Meilen on the Lake of Zurich, and Robenhausen on the lake of Pfaffikon. Yet no jade has been discovered among the rocks of the Swiss Alps; neither have any chippings been found which might lead us to suspect that the stone was worked in Switzerland. As it seems beyond doubt that the jade must be a foreign material, it becomes an interesting question to determine whether such objects were obtained by barter, or had been brought by the ancestors of the old lake dwellers from their primitive abode in the east, and preserved generation after generation during their migration westwards. It should be mentioned that jade celts have been found by Dr Schliemann among the relics of the oldest of the cities at Hissarlik. A jade celt engraved with a Gnostic formula in Greek characters is preserved in the Christy collection; and among the Assyrian and Babylonian seal-cylinders in the British museum there is said to be one specimen of jade.
It was shown by M. Damour, in 1863, that much of the so-called jade is altogether different from nephrite, and must be separated as a distinct, species, for which be suggested the name of "jadeite." Jadeite is a silicate of aluminum and sodium, and therefore differs widely from nephrite in chemical composition. Mineralogically its relations lie rather with epidote than with hornblende. Its color is generally brighter than that of nephrite, and the paler-tinted kinds often contain veins of a bright-great color. It is slightly harder than nephrite, but its most distinctive characteristic is its high specific gravity; this ranges from 3-28 to 3.35, while the density of nephrite even in oceanic jade, never exceeds 3.18.
Much of the Chinese "jade" is really jadeite. According to Pumpelly the jadeite of Yu-nan in south-west China is known as fei-tsui. Jadeite also occurs to the north-west of Bhamo in Burmah. Axes of jadeite are not unfrequently found in the remains of the Swiss lake-dwelling, but the mineral is not known to occur in the rocks of Europe. Jadeite forms the substance of many ancient Mexican ornaments, while implements wrought in the same material have been found in Costa Rica. Fischer records an Egyptian scarabaeus in jadeite.
The green jade-like stones which are known to the Maories as kawa-kawa ang tangiwai do not appear to be either jade or jadeite. From analyses published by Von Hochstetter, the former is a hydrated silicate of aluminum and magnesium, while the latter is a silicate of aluminium, calcium, magnesium, and iron.
It was pointed out by Damour, in 1865, that certain stone celts found in the dolmens of France and in the lakes of Switzerland, as well as some from Mexico, are wrought in a material which resembles jadeite, but contains a larger proportion of iron, and is marked by having a specific gravity as high as 3-4 or even 3.65. this substance he distinguished as chloromelanite, a word which has an unfortunate resemblance to the name chloromelan which Breithaupt bestowed, as far back as 1823, upon a mineral resembling constedite. Damours chloromelanite is a substance of spinach-green or blackish green color, frequently iron-pyrites. When H.B. de Saussure examined the geology of the Swiss Alps, he found a greenish mineral, of singular toughness, which he described as jade. By Hauy it was afterwards called jade tenace. Its chemical composition, however, is quite unlike that of jade, and Beudant separated it as distinct mineral under the name of "saussurite." Placed by the older mineralogists among the felspars, it seems to take its right position with the species called zoisite. Saussurite is a silicate of aluminium and calcium, having a specific gravity of about 3.2. It forms a constituent of the Alpine rock known as "euphotide," boulders of which are scattered around the Lake of Geneva, and were used by the lake-dwellers in the manufacture of implements.
Another mineral occasionally mistaken for some of the paler kinds of jade, and used as a material for implements by the Beolithic occupants of western Europe, is the species termed "fibrolite." This is a silicate of aluminium with a specific gravity of about 3.2 a density serving to distinguish it from quartz, while it ,may be separated from other jade-like minerals by its infusibility.
The following table, containing a few selected analyses of jade and the other minerals mentioned in this article, may be useful for reference.
I. White Jade, China; Damout
II. Whiute jade, Turkestan ; L.R. von Fellenberg
III. Green jade, New Zealand; Fellenberg
IV. Green kade Swiss Lake-dwelling; Fellenberg
V. Oceanic jade, Damourm Fellenberg
. S.g. 3.18
VI. Jadeite, China;
. S.g. 3.34
VII. Chloromelanite, stone celt; Damour
VIII. Saussurite, L. Geneva; T. Stery Hunt,
IX. Fibrolite, celt from Morbihan; Damour,
The literature of jade is very extensive, but it will be sufficient to refer to the work of Heinrich Fisher, which is almost exhaustive of the subject: Nephrit und Jadeit, nach ihren mineralogischen Eigenschaften sowie nach ihrer urgeschichtlichen und ethnographischen. Bedeutung, 2d ed., Stuttgart, 1880. ( F.W.R.*)
The above article was written by Frederick W. Rudler, F.G.S., Curator and Librarian of the Museum of Practical Geology from 1879; of the Museum of Practical Geology, Jerymn Street, 1861-76; assistant director of Ure's Dictionary of Arts and Manufactures; joint author of Stanford's Europe.