In China, jade is synonymous with beautiful stones. The ancients regarded jade as a treasure, and today people call precious jade Baoyu. China is a country of jade, but at present, there are differences in the definitions of jade, jade and precious stones in the domestic jewelry, archaeology and geology circles. At present, jade in the world refers to nephrite and jadeite (jadeite), and other jade carving stones are collectively referred to as jade. Gem is a collection of one or more minerals with special optical effects, and most of them are single crystals of certain minerals, such as diamond, ruby, sapphire, emerald, opal, tourmaline, purple tooth black and so on.
First, jade
Emerald, commonly known as "Emerald" in China, is a rising star in traditional jade in China, and also the top grade in all modern jade.
Emerald, whether it is "mountain material" (primary ore) or "seed material" (secondary ore), is mainly a dense block composed of jadeite minerals. Under the microscope, jadeite minerals that make up jadeite are closely intertwined, forming a fibrous structure of jadeite. This compact fiber structure makes jadeite delicate and tough.
Common jadeite colors are white, gray, pink, light brown, green, emerald green, yellow-green, purple and so on. Most of them are opaque, partly translucent and glassy. According to the color and texture, there are more than 20 varieties, such as sapphire green, brilliant green, boxwood green, sunny green, glazed green, Ying Ge green, spinach green, shallow water green, shallow sunshine green, frog green, melon skin green, plum green, blue-green, grayish green, oil green, violet, lotus root powder land, etc.
Second, nephrite
Nephrite has white jade, sapphire, jasper, topaz and jet in China. Different from jadeite, they are compact blocks composed of tremolite actinolite minerals (mainly tremolite) in amphibole group minerals. Observing under the microscope, nephrite, like jadeite, has a fibrous structure. This fibrous structure composed of tremolite or actinolite is the main reason why nephrite has fine and tough properties.
The common colors of nephrite are white, gray, green, dark green, yellow and black. Most of them are opaque, and some are translucent and glassy. The varieties of nephrite are mainly divided according to different colors. The best white jade, as white as sheep fat, is called "sheep fat jade". Sapphire is grayish white to bluish white. At present, some people call it "blue white jade". Jasper is green to dark green, and sometimes black spots can be seen, which is caused by impurities such as chrome spinel minerals. Containing many impurities, when it is black, it is a precious jet. Topaz is also a precious variety. Sapphire has a yellow shell of sugar water, and some people call it "sugar jade". When white is slightly pink, some people call it "pink jade". Tiger skin color is called "tiger skin jade" and so on.
Xiuyan jade, called Xiuyu for short, is named after Xiuyan County, Liaoning Province. On the surface, the main variety of this kind of jade is similar to sapphire or jasper in Xinjiang, but its mineral composition and hardness are different. The main mineral that makes up Xiuyu is serpentine. The composition often contains ferrous and trivalent iron, and is also mixed with impurities such as manganese, aluminum, nickel and cobalt, which makes xiuyan jade have various colors. The colors of jadeite are white, yellow, light yellow, pink, light green, green, emerald green, dark green, brown green and other variegated colors. Among them, green tones are often dominant, and the color is between sapphire and jasper. The serpentine minerals that make up Xiuyu usually account for more than 85%, and a small amount of calcite, tremolite and other minerals are common. The mixing of tremolite can increase the hardness of xiuyan jade.
The five qualities of Xiuyan jade are exquisite, translucent to opaque, waxy to glossy. The hardness is 2.5 ~ 5.5 and the specific gravity is 2.5 ~ 2.8. The average refractive index of serpentine minerals is 1.54 ~ 1.55. Serpentine is an metasomatic alteration mineral of magnesium carbonate rocks, magnesium basic rocks and ultrabasic rocks, and can also coexist with talc and chlorite.
Jade in xiuyan jade is easily distinguished from jadeite and nephrite, mainly because of its luster (oily luster) and hardness.
The history of jade mining in South China is unknown. Because it is produced in Liu Si, Xinyi County, Guangdong Province, it is also called "Xinyi Jade". Jade is mostly composed of serpentine, and contains a small amount of phlogopite, talc, calcite, tremolite, chlorite, epidote and so on. Because of many impurities, the color is often different from Xiuyu, and the tone is dark green to brownish green. At the same time, the geological conditions are different from those in xiuyan jade. It occurs in the stratum composed of mica schist and banded mixed gneiss, and there is often a talc layer with a thickness of 0.2 ~ 5.5 meters under the jade ore body.
Qilian jade is produced in Qilian Mountain, with dark green color and many black spots, which are not found in xiuyan jade and Nanfang jade.
Beijing topaz is light yellow and also made of serpentine. It is named because it is produced in the contact metamorphic marble of Laojuntang in the Ming Tombs of Beijing. It was discovered in the 1960s, and it is unknown whether it has been mined in history. Mining has stopped because of too little output.
Anle jade is also a serpentine jade, named after it was first discovered in Lvshui River, Ji 'an County, Jilin Province. It appears in the ancient strata of serpentine marble. Jade is pure, delicate and smooth, apple green to dark green, slightly transparent to translucent.
There are many places of origin and varieties of serpentine jade similar to Xiuyu jade. Therefore, when we identify jade articles belonging to this kind of jade since the Neolithic age, we must not easily determine the source of jade. During the period of 1977, among the Neolithic jades found by Nanjing Museum in Caoxie Mountain and Zhangling Mountain in Wuxian County, Jiangsu Province, 1 jade tube was identified as serpentine jade, which was not produced in Liaoning Province, and the jade material may be produced in Zhenjiang, Jiangsu Province.
Fourth, lantian jade.
Lantian jade's name first appeared in History of Han Geography, and beautiful jade was produced in Lantian Mountain in the north of Beijing (now the north of Xi 'an). Later, there were records of Lantian's jade production in ancient books such as Biography of consorts in the Later Han Dynasty, Zhang Heng's ode to Xijing, Guangya, Notes on Water Mirror and Yuanhe County Records. During the Wanli period of the Ming Dynasty, Song said in "Heavenly Creations": "The so-called Lantian is the alias of jade in Qingling (Kunlun Mountain), which was later mistaken for the Lantian of An. "Since then, it has caused disputes for later generations. Some people say that Lantian doesn't produce jade at all, and some people say that even if it produces jade, it may be laiyu (green jade with a color like a vegetable leaf). In recent years, Shaanxi geologists have discovered serpentine marble jade in Lantian, which is regarded as an ancient recorded lantian jade (1978165438+1People's Daily on October 23rd). This discovery not only attracted the attention of geologists looking for raw materials of Yuzhu, but also attracted the interest of archaeologists. 1982 geological museum, Ministry of Geology and Mineral Resources, exhibited the above-mentioned lantian jade rough stone. When this serpentine is strong, some parts have become jade like Xiuyu. From the appearance, jade has uneven tones such as yellow and light green, accompanied by light white marble. Although this kind of jade is not very beautiful, it is easy to process because Lantian is located near the ancient city of Xi 'an.
Verb (abbreviation of verb) nanyangyu
Nanyang Jade is named after its production in Nanyang, Henan Province, and its mining area is Dushan, Nanyang, so it is called "dushan jade".
Nanyang jade has bright color, fine texture, good luster and high hardness, which can be compared with jadeite. Germans once called it "Nanyang Emerald", and Soviet geologist Kivlinko once classified Nanyang jade as jadeite jade deposit. According to the research of Henan geologists in recent years, Nanyangyu is an altered plagioclase, which consists of zoisite, epidote, tremolite, sericite, biotite and sphene. Through microscopic identification, jade contains a variety of altered minerals, mainly zoisite, epidote and tremolite. Because jade contains all kinds of metal impurities, there are many colors of jade, mainly green, white and variegated, as well as purple, blue and yellow.
Sixth, turquoise.
Turquoise is a cryptocrystalline dense block, which is mainly composed of fine turquoise minerals and contains phosphate of copper, aluminum and water, and usually occurs in secondary epithermal deposits. Most of them are sky blue, dark blue, blue-green and green, and those with strong weathering are green and white. It has a soft waxy luster. Hardness 6, specific gravity 2.6 ~ 2.8. The average refractive index is 1.6 1 ~ 1.63.
Turquoise is also an ancient traditional jade in China. As early as the Neolithic Age, it was used as an ornament with jade such as sapphire and agate. According to the statistics in The History of Ancient Mining Development in China, turquoise ornaments have been found in many places from Qijia Culture and Dawenkou Cultural Site in the late Neolithic Age to tombs in the Southern and Northern Dynasties.
Seven, agate
Agate has been decorated by people since ancient times because of its beautiful stripes. Among the unearthed jade articles, strings of agate beads are more common, mostly necklaces.
In addition to chalcedony, sometimes a small amount of opal or aphanitic granular time is found in the fine minerals that make up agate. Strictly speaking, without the characteristics of grain and pattern, it can't be called agate, but chalcedony. Now some chalcedony without grain and pattern on the market is also called "agate", which is inconsistent with the meaning of ancient agate. Pure agate is white. Because it contains other metal elements (such as iron and nickel), it is gray, brown, red, blue, green, emerald, pink green and black, and sometimes several colors are mixed or appear alternately. Agate blocks are transparent, translucent and opaque, with glassy to waxy luster. The hardness is 6.5 ~ 7 and the specific gravity is 2.65.
There are many kinds of agates according to the thickness and shape of stripes. Those with onyx stripes are called onyx, and those with red stripes are the most precious, called red onyx. In addition, there are strip agate, city agate, Tanagate, moss agate, red agate, zygote agate, sauce agate, cypress agate, arc agate, water bile agate and other varieties (Li See Compendium of Materia Medica
In the "chalcedony" without grain and pattern, there are also many jade raw materials. According to different colors, there are "carnelian", "chrysolite" (also known as flesh color), "chrysolite", "blood chalcedony" (also known as blood stone) and "jasper".
Agate, like nephrite, is a traditional jade in China. There are agate cups and agate beads in the jade unearthed from the ruins of Nanjing Beiyinyangying. Among a large number of agate beads, one is made to ward off evil spirits, with a length of 1.7 cm. Agate ornaments were also found in Qijia Cultural Site in Dahezhuang, Yongjing, Gansu, Chunqiu Tomb in Dadian, Junan, Shandong and Jin Dong Tomb in Xiangshan, Nanjing.
Eight, lapis lazuli
Lapis lazuli jade material is composed of lapis lazuli minerals, often containing calcite, pyrite and sometimes a small amount of diopside. Lapis lazuli jade material is produced in Afghanistan, and the average content of lapis lazuli mineral accounts for 25 ~ 40%. Emerald is blue, dark blue, light blue and ultramarine. Opaque, glassy to greasy luster. The hardness is 5.5 and the specific gravity is 2.7 ~ 2.9. Dark blue is thick but not black, which is called "green gold"; When the content of deep blue and pyrite is more than lapis lazuli mineral, it is called "Jingelang"; Light blue and white calcite (generally excluding pyrite) is called "birthstone" (this name comes from the ancient saying that lapis lazuli was used as a childbirth medicine).
Nine, Bidianzi and Malachite
Fifty-six-year volume of Summary of Reading Historical Records: "Tianzhu Mountain is fifty miles west of Zhou (Xing 'an Prefecture, now Ankang County, Shaanxi Province), and there are more than 20 temples and caves under it. Tributes were paid in the Tang and Song Dynasties, and the dynasty was sealed in the early Ming Dynasty. " Xia et al. thought in the History of Ancient Mining Development in China: "Bidian in Yuan Dynasty was not a shop, and Bidian in Ming Dynasty was no exception. "This is because turquoise (ideas) generally does not coexist with malachite (turquoise, also known as" stone green "), and malachite often coexists with malachite. Since it is known that Bidian was born with malachite, Bidian or Bidianzi probably refers to malachite.
Malachite is a secondary oxidized mineral, which usually occurs in the upper oxidation zone of copper mine. Malachite is named after its color is malachite green, which is mostly in the form of blocks, stalactites, shells and concentric strips. The hardness is 4 ~ 6 and the specific gravity is 3.9 ~ 4. It often coexists with limonite, calcite, manganese soil, chalcedony and chrysocolla.
Chrysocolla is also a secondary mineral, mostly formed by chalcopyrite and tetrahedrite, which was changed by the hot solution of alkaline silicate. It is green, blue-green to sky-blue, usually opal or enamel-shaped, but there are also mud or grapes. The hardness is 2 ~ 4 and the specific gravity is 2 ~ 2.24. Opaque as malachite, glassy to earthy. good luck