Silicified wood is also called wood fossil. Trees hundreds of millions of years ago were buried deep underground for various reasons. In the stratum, chemicals around the trunk, such as silicon dioxide, iron sulfide and calcium carbonate, enter the trees under the action of groundwater, replacing the original wood components, retaining the shape of the trees, and forming wood fossils through petrochemical action. Because it contains many silica components, it is usually called silicified wood. This substitution is so accurate that it not only reflects the external shape, but also reflects the internal structure, and sometimes even determines the cell structure. The technical term of this replacement is "replacement", which refers to the process of simultaneous dissolution and precipitation, so that one mineral replaces another. The formation of silicified wood is a process in which silicon replaces wood fiber. Silicified wood is also a kind of fossil, which retains some characteristics of ancient trees and provides clues for us to study the history of ancient plants and paleontology, as well as geological and climate changes. Siliceous fossils are common, and there are silicified wood national parks in many countries.
In the meantime, calcium and other components are filled, but it is not an metasomatism reaction.
Silicified wood was in Jurassic period10.50 billion years ago. When plants (mainly conifers, cycads, ginkgo biloba, ferns, seed ferns, etc. 1.5 or more) are buried by sediments, wood is not easy to rot because it is in a dry and water-deficient environment, but in the long petrochemical process, wood fibers are alternated by minerals such as silicon dioxide, calcium carbonate and iron sulfide. It is an unprocessed wood fossil.
It is difficult to find this kind of tree-shaped jade in the market, because only the tree-shaped jade with a particularly good shape is not used for processing, and the one with a particularly good shape is rare. Because wood fossils themselves are fossils of trees, trees have bark, and these barks are pale and boring, which is very unsightly.
Only by peeling off the surface and polishing can we show the beauty of Huamu jade. By analyzing the identification results of thousands of specimens and related data, the author found that the main mineral species of wood fossils are Yingshi, followed by chalcedony and opal.
Mineralogical classification is: timely wood fossils, chalcedony wood fossils and opal wood fossils.
From the analysis of the residual structure of wood fossils, some opal wood fossils have been transformed into timely wood fossils, and there are still bending cracks under dehydration. Due to age, stress, high temperature and aging, the opal wood fossils formed in Mesozoic have been transformed into timely wood fossils, and only the Cenozoic opal wood fossils have been preserved. white
The mineral has high purity, uniform particle size, single composition, light cell residue and little cell wall residue. Cell morphology is mainly judged by the cell contour formed by timely replacement, filling and accumulation of chalcedony. Most of the tree species are non-fat-producing plants such as Metasequoia glyptostroboides and Ginkgo biloba, and the later impregnation effect is weak. White wood fossils are rare.
grey
Minerals have high purity, uniform particle size, single composition, deep cell residual color and many cell wall residues. Cell morphology is mainly judged by the cell contour and obvious cell wall formed by timely and chalcedony replacement, filling and accumulation. Most of the tree species are non-fat-producing plants such as Metasequoia glyptostroboides and Ginkgo biloba, and the later impregnation effect is strong. Gray wood fossils are common.
red
The red mineral phase of Fe2O3 makes wood fossils appear red. It is rare that the whole wood fossils are red, and most of them are patchy, variegated or clustered. When wood fossils are full of chalcedony, they often show agate-like appearance.
yellow
Tree species are mainly fat-producing plants such as conifers and cypresses. Yellow is evenly distributed in wood fossils, which is consistent inside and outside, and is related to the original wood. Yellow wood fossils are common. Another yellow wood fossil. Because of the yellow mineral phase of Fe2O3, wood fossils are yellow and uneven, which can be divided into shallow and deep.
brown
The brown mineral phase of Fe2O3 makes wood fossils brown. Among wood fossils, few are brown as a whole, and most are patchy, variegated or clustered.
green
After soaking with CuC03, the wood fossils are green. Malachite is attached to the surface and cracks of wood fossils in the form of thin films, which are often distributed in sheets, but also in patches and spots.
Agate shape
A kind of "agate fossil" is reported, which does not exist in nature and its origin is quite different. When dense and delicate chalcedony fossils are impregnated with iron oxide in the later stage, sometimes iron oxide will be impregnated and attached to the distribution of tree rings, which looks like agate. This kind of wood fossil with jade texture can be called "agate-like wood fossil".
A number of "agate-like timely chalcedony fossils" have been detected, including red, maroon, light brownish yellow, milky white, dark black and gray, and several colors are mixed or regularly distributed. Due to the strong silicification, there are few cell structures of lignocellulose, and some of them can be seen as annular rings and cell morphology. After polishing, it is fine and smooth, and has a strong sense of jade. Most of them are composed of timely and chalcedony minerals, but they are shaped like agate rather than agate.
Agate has been given a specific definition and formation mechanism in minerals and petrology. Agate is a secretory substance, which grows and crystallizes from outside to inside in a certain space (mostly circular), and the crystals fill the whole cavity. The typical feature of secretory body is a color ring with concentric layered bands. In the process of secretion, SiO2 _ 2 gel slowly precipitates and crystallizes in the cavity, and some timely clusters grow on the wall of the central cavity. If there are certain pores and cavities in wood fossils or in the contact parts with surrounding rocks, local agate crystals can also be formed, but from the whole trunk, there is no geological environment for agate formation.
Agate mostly occurs in the pores of volcanic rocks; Silicate caves in sedimentary rocks; Wall end of chronotropic crystal cluster in hydrothermal chronotropic vein. At the junction of Yunnan, Guizhou and Sichuan provinces, nearly 500,000 square kilometers, there are Permian Emeishan basalts. In a kind of pore basalt, the filler in the pores is agate of various colors, and the rain flower stones are mostly agate. In the amethyst cluster holes rich in Brazil, there are strips of agate distributed at the wall end. Silicified wood is mainly produced in Mesozoic, most in Jurassic and Cretaceous. According to the data analysis of China 1: 200000 regional geological map, Jurassic and Cretaceous are distributed in all provinces of China, so the geographical distribution of silicified wood should be in all provinces. The artificial silicified wood in various places is constantly expanding due to certain demand, and there are traces of silicified wood everywhere in the flower stone market all over the country. The following only collects some data on the output of silicified wood in situ and in different places to show the universality of distribution.
1), Jurassic and Cretaceous silicified wood fossils from Jinhuakan and Xishuiliang Village, Chishui, Guizhou.
2) Silicified wood of mangrove in Feixian County, Linqu, Shandong Province, with a trunk length of 12m and a diameter of 0.40m ..
3) Dashanpu, Zigong City, Sichuan Province is a gathering place of Jurassic dinosaurs, and also produces silicified wood, with a trunk of more than 20 meters.
4) There is a strange soil forest in Yuanmou County, Yunnan Province, and the gravel in the soil forest is also found to be silicified wood.
5) A national geological park featuring Cretaceous landforms will be built in Jingling Anxi, Xinchang County, eastern Zhejiang Province.
Silicified wood fossils are distributed nearly seven kilometers north and south. The trunk of silicified wood exposed from the ground is more than one meter long, and it takes four or five people to enclose it. Part of the root system is exposed at the bottom of the upright silicified wood, and the trunk of another pine tree is more than 10 meter long and more than 2 meters in diameter. The annual rings are faintly visible, and even the traces of bark and insects have been preserved.
Rock-piercing silicified wood forest is composed of pine, cypress, Chinese fir, ginkgo and birch, which is from Jurassic to Cretaceous geological age of 70 million to 200 million years ago. Not long ago, washed silicified wood was found in Chengtan River area.
A rare new species of silicified wood was discovered in Xinchang county. Duan Shuying, a researcher at the Institute of Botany, Chinese Academy of Sciences, named it "Xinchang Aralia wood".
6) A rare silicified wood in the Central Plains was found next to Bailong Temple in Jinxi Village, Huanglushan Township, Xiaolangdi Scenic Area of the Yellow River in Mengjin County, Henan Province. Dark red, with a diameter of 1 m, and the exposed part is 2.5m high.
7) A large number of paleontological fossils, including mammoths, bison, wild horses, hairy rhinoceroses, antelopes and silicified wood, were found in a construction site in Harbin Electric Power District, Heilongjiang Province.
8) Two giant silicified wood plants were found in the Gobi desert of Naomaohu Lake, which is more than 0/00 km north of Yiwu county in eastern Xinjiang. At least 65438+500 million years ago, roots, trunks, barks and branches were well preserved. One plant is17m in length and1.05m in diameter, the other plant is1.5m in length and1.5m in small head diameter.
9) In the Flower Grand View Garden of the 5th China Flower Expo in Chencun, Shunde, Guangdong, a strange silicified wood was exhibited, which was about 1.37 ~ 1.95 billion years ago and was produced in the Gobi Desert of Naomaohu Lake in Yiwu County, Xinjiang Uygur Autonomous Region, with a length of 1 6.7m, a root diameter of 2.3m and a top diameter of/kloc.
10), Shenzhen Huxian Botanical Garden established a remote silicified wood ancient botanical garden, covering an area of 20,000 square kilometers. More than 500 Mesozoic silicified trees from Liaoning, Xinjiang and Inner Mongolia in Huxian Botanical Garden belong to conifers. On the second floor, the specimens of ancient plant evolution and evolution with the theme of silicified wood are displayed, showing the plant ecological environment of Mesozoic and Cenozoic on the earth.
1 1), the imperial garden of the Palace Museum in Beijing is also decorated with silicified wood in different places.
12), Chencun Flower World, Shunde City, Guangdong Province, transplanted different silicified wood.
13), a collector of silicified wood fossils in Shanghai, owns more than 10,000 silicified wood fossils. Silicified wood is not only produced in China, but also comes from more than 50 countries and regions. One of them needs three hands to collect silicified wood roots, and the other collects silicified wood with a trunk height of about two meters and a trunk diameter of more than one meter, which is unique in that more than two-thirds of the trunk is silicon.
14), silicified wood in Shisongping, Lu Yong Township, Yongchuan County, Sichuan Province, with a maximum trunk diameter of1.25m and a length of1.12m. ..
15), 10 A hilly area north of Quyang County, Hebei Province, south of Xidayang Reservoir, and at the junction with Tangxian County. Silicified wood is distributed on several slopes two or three kilometers long from north to south, with clear annual rings.
16), the silicified wood in Rizhao City, Shandong Province is produced in Beijian Village-Xiao Mu Village, Dashitou Township, Juxian County, and Zhushan Village, Qishan Township. It is mainly produced in the area from Nanzhongjia to Donghoujiagou Village, Shichang, Wulian County,1350,000 years ago, and the production horizon is Yangjiazhuang Formation of Laiyang Group.
17), Mashan Nature Reserve in jimo city, Shandong Province, located at the junction of Daxin Town and Yingshang Town in the west of jimo city, with silicified wood. The plant 1 1 has been found, belonging to the family Meretridae, and the exposed stratum is the Qingshan Formation of the Early Cretaceous.
18), produced in silicified wood fossils near Laoshidan Coal Mine in Wuhai City, Inner Mongolia Autonomous Region, with a trunk length of 38 meters.
19), there are silicified wood fossils10.40 billion years ago in the Hashun Gobi Desert in the southwest of Hami City, Xinjiang Uygur Autonomous Region, on the landform of Ya Dan and in the place called "ghost town".
20) Silicified wood was exposed in Yuechangshanling Quarry, Zigong City, Sichuan Province, and was discovered by quarrymen in September. 1983. One trunk is 23.3 meters long and belongs to Ginkgo biloba, with the largest diameter of 1.3 meters and 10 small branches, with high carbon content in the upper part and poor surface preservation. The other is a conifer, with a length of 13m and a maximum diameter of1.08m. The silicified wood was buried in the sandstone at the bottom of the Lower Shaximiao Formation of the Middle Jurassic 654.38+600 million years ago, adjacent to the Dashanpu dinosaur fossil group.
2 1), Beijing Museum of Natural History plans to build an agate chalcedony silicified wood stone forest in different places on the green space in front of the exhibition building, which is expected to be completed in June. These silicified wood originated in Beipiao, Liaoning Province, about10.3 billion years ago. The total length of the silicified wood trunk is about 40m, and it is divided into 10 sections, with the longest section being 1 1 m and the largest diameter exceeding 1 m..
22) There is a cypress silicified wood next to Wang Yue Temple in West Lake, Hangzhou, which was planted in front of the storm pavilion where Yue Fei was killed.
23) The fossil of Mesozoic Jurassic silicified wood in Wangping Town, Yongchuan City, Sichuan Province, the plant name is Lycopodium, and Du Fu once wrote "Evergreen Pine Fossil".
24) Silicified wood fossils are produced in Daping Town, Hua 'an County, Fujian Province, 23 kilometers away. The ancients described the characteristics of pine fossils as "there are pine scales vaguely, and stones speak with their hands." The geological age is one hundred and fifty years ago, belonging to Jurassic. According to local villagers, there are many fossils of Pinus bungeana in the mountain, and this billion-year-old pine near the water is more eye-catching because of its height.
There is a natural bamboo garden 68 kilometers southeast of Yibin City, Sichuan Province. There is a bamboo with a thick bowl, and branches are piled on the roots. Lush, covering more than 500 hills with a total area of more than 60,000 mu, this is a rare bamboo sea in southern Sichuan at home and abroad. There are exposed silicified wood groups in Erlongkou Township, northern Zhuhai, which are distributed within 4 square kilometers.
26) The remote silicified wood stone forest in Yunlong Park, Pengcheng, Xuzhou, Jiangsu Province covers an area of more than 2,000 square meters, and more than 0/00 trees have been transplanted in different places, some of which are about 10 m high and about10.5 m in diameter, with an investment of10.3 million yuan.
27) In Zhangzi County, Shanxi Province, silicified wood is produced in the hills around Sunan Village and He Zi Village, which are 0/0 km away from Cheng Ju/KLOC-0. The plant is cypress. There are 43 trees exposed on the ground. The longest 13.9 m, the shortest about 2 m, the thickest 1 m and the thinnest 0.5 m. Some branches and rings are clearly distinguishable. In order to open up new tourist attractions, Shanxi decided to build a museum of silicified wood fossils in its producing area, and the design scheme is under way.
28), Taiyuan City, Shanxi Province, Shanxi Provincial Museum 1982 approved a piece of 1 1 meter-high silicified wood fossil.
29)13.9m silicified wood fossil, which was collected in southeastern Shanxi Museum on 1985, is now installed in Chenghuang Temple, East Street, Changzhi City for visitors to enjoy.
30) Mamenxi dinosaur in Anyue County, Sichuan Province is the second largest late Jurassic dinosaur fossil in Asia. There are other fossils related to silicified wood, elephants, pandas, fish turtles and so on 65438+400 million years ago.
3 1), the silicified wood forest in Lushun Museum Park, Liaoning Province, invested by Dalian Municipal Government, is scheduled to be exhibited in the first half of 2003. Silicified wood came from beipiao city, Liaoning Province, about1.6-1.800 million years ago. There are 65,438+09 species of silicified wood, including cedar and golden pine. The trunk is 6 meters long and the diameter can reach 1.5 meters.
32) Flower Island in Sancha Lake, Jianyang, Sichuan Province, a rare tree species contemporary with dinosaurs, silver fir, silicified wood 65.438+0.5 billion years ago. 33) Sihetun, about 40 kilometers away from beipiao city, Liaoning Province, is a villagers' group in Caomidian Village, Shangyuan Town. Its rich paleontological fossils make it occupy a place in the world paleontology. The exhibition hall displays various plant fossils, silicified wood, insect fossils, reptiles and primitive mammal fossils in the Jehol biota.
34), dragon three Tower in Chaoyang County, Liaoning Province, parrot beak, Chinese bird, sturgeon, mackerel, silicified wood and insect fossils.
35) Shen Kuo of Song Dynasty in Yan 'an City, Shaanxi Province recorded in his "Meng Qian Bi Tan" that hundreds of petrified trees were found in Yongningguan, Yanzhou (now Yan 'an City, Shaanxi Province).
36) There are many Shisongping hills in Lu Yong Township, Yongchuan County, Sichuan Province, with the largest trunk diameter1.25m and length1.12m. ..
37) During the Mesozoic era in Yongkang, Zhejiang Province, plants flourished, and a large number of dense forests were buried underground by repeated strong orogenic movements, forming silicified woody plants, such as pine, cypress and camphor.
38), Yunnan Hibiscus Silicified Wood, the stem of early Permian precious tree fern discovered in Kunming, Yunnan, is preserved in Permian basalt, and the main body is preserved in situ, to be developed into a relic museum.
39) The remote silicified wood forest in the north of the ancient pagoda park in Jinzhou, Liaoning Province covers an area of more than 4,000 square meters. Silicified wood was formed 65.438+0.5 billion years ago, with more than 200 plants, thick trunks and a diameter of more than one meter, most of which came from the fossil group in western Liaoning.
40) In Tianshan Valley, Wenquan County, Bortala Mongolian Autonomous Prefecture, Xinjiang Uygur Autonomous Region, a large number of silicified wood and marine biochemical stone groups dating back to10.30 billion years ago were found, with a distribution area of 6 square kilometers, close arrangement of trees, clear texture and a diameter of about 2 meters.
4 1), a construction site in Harbin Power Zone, Heilongjiang Province, found mammoths, bison, wild horses, hairy rhinoceroses, antelopes and silicified wood more than 20,000 years ago.
42) The ancient imperial garden in Qixia Mountain Scenic Area of Nanjing covers an area of more than 30 mu. It used to be the palace of Qianlong, and there is a precious silicified wood in a different place.
43) 65438+300 million years old silicified wood in Mianershan, Minhou, Fujian.
44), Baise, Guangxi, about 800 thousand years ago, a huge meteorite hit southeast Asia, causing molten debris to splash and the earth to burn everywhere. The fire destroyed the dense forest in Baise basin, exposing the gravel layer below. According to the laboratory analysis, the preservation degree of carbon chips and silicified wood chips is exactly the same as that of paleolithic and glass meteorites. Archaeologists believe that there was a meteorite hitting the earth in Baise Paleolithic Age.
45) The Black Oil Mountain in the northeast of Karamay City, Xinjiang Uygur Autonomous Region was formed more than 654.38+0.8 million years ago, that is, during the Jurassic and Cretaceous periods. In 654.38+0983, there was a "Tuo Lake" in the park of 654.38+03 million square meters at the southern foot of Heiyou Mountain. There were two small islands in the lake, called "Island" and "Zu Island" respectively. There are three silicified pine trees formed 200 million years ago on Zu Island.
46), Changzhou Jurassic Dinosaur Park, using electricity, sound and light technology, created Jurassic vegetation and various dinosaur simulation models, and transplanted more than 100 silicified trees of different sizes in different places.
47), Beijing Wood Fossil, produced in Delong Bay, Qianjiadian Village, Yanqing County, Beijing. Most of the stones are exposed to the ground vertically, with a maximum diameter of 2.5 meters and a minimum of several tens of centimeters, generally 0.5 ~ 1.0 meters. Colors are grayish white, gray and brown. On its cross section, there are regular, beautiful and dense clear annual rings; In the longitudinal section, there are fine longitudinal textures and uneven fossil bark, and the thickness is about 65438±0cm.
48) The Qitai Silicified Wood Group in Qitai County, Changji Hui Autonomous Prefecture, Xinjiang Uygur Autonomous Region is located in the center of the world's rare Fuyun-Qinghe-Jimsar-Qitai-Rem-Barkun-Hami-Yiwu Silicified Wood Enrichment Zone. The silicified wood here is famous for its concentrated distribution, huge quantity and scale, and extremely complete preservation. There are nearly a thousand trees exposed in the park's silicified wood scenic spot with an area of only 1 1.65 square kilometers, which is one of the most spectacular silicified wood groups in the world. Qitai silicified wood was produced in sandstone and mudstone of Shishugou Group in Jurassic period about 654.38+0.5 billion years ago. The original structure of this tree is well preserved. Silicified wood is generally 0.5-654.38+0m in diameter, up to 2.8m in length and 5-20m in length, up to 25m in length. Different burial states, such as lodging and standing, reflect the dense forest landscape in the river and lake environment of the basin in ancient times.
49) From June, 5438 to February, 2005, the Ministry of Land and Resources officially approved Sichuan Shehong Silicified Wood Geopark as a national geological park, and in the same year it was named "National Science Education Base" by the Chinese Paleontological Society. The park has the largest and most well-preserved silicified wood group in southwest China, with beautiful canyon landscape, water landscape, natural ecology and human landscape. There are more than 550 silicified wood relics in more than 20 places in the park.
50) There stands 6 19 silicified wood in the water cave scenic spot of Benxi National Geopark in Liaoning Province, which is the largest silicified wood in the world, with a height of14.7m and a diameter of1.5m. 。
Archaeological doubt
Q: The concept of "jade" seems to be very confusing in the gem industry. There is a saying of "Mu Shi Yu" in the market. You are a well-known senior archaeologist at home and abroad. Please explain the concept of "Mu Shiyu" from the perspective of historical archaeology.
Zhao: Regarding the concept of jade, the academic circles are not completely unified in their use, which reflects the gap in people's understanding. Generally speaking, the understanding of jade can be divided into three kinds: traditional theory, narrow sense theory and broad sense theory.
The traditional theory is the ancient people's understanding of jade, which can be represented by Xu Shen's statement in Shuo Wen Jie Zi that "the beauty of stone has five virtues". At this time, on the basis of summarizing the predecessors' theories of "Eleven Virtues" and "Nine Virtues", this paper puts forward that some high-quality stone materials that cannot be called jade are called "stone is second to jade", "stone is like jade" and "beauty of stone" respectively. For thousands of years, in the traditional culture of China, ancient ancestors mainly adhered to this understanding; Narrow sense mainly refers to jadeite and nephrite. Jade mainly refers to jade. Nephrite mainly refers to hornblende jade represented by Hetian jade; Jade in a broad sense generally refers to a variety of crystal-microcrystalline mineral aggregates with bright colors suitable for carving and a small amount of amorphous organic matter, which has the characteristics of beauty, durability and rarity, including nephrite, jadeite, colored stone, organic gemstone and so on. Organic gems, also known as biomass gems, refer to fossils or other biological relics, such as coal concentrate, amber, silicified wood and so on. , is formed in geological history, with biology as the main component, which meets the requirements of arts and crafts.
The so-called wood stone jade refers to those silicified wood with bright colors, strong luster, clear wood structure and dense and tough texture. Silicified wood is a kind of petrified jade, also known as wood fossils, tree fossils, tree jadeite and so on. Among them, the buried trees are silicified, the secondary xylem tissue is replaced by silicon dioxide (SiO2 _ 2), and the residual structure of wood is preserved.
Q: Silicified wood can not only make fossil ornaments, strange stone ornaments and jade ornaments, but also cut and polished to make silicified wood jewelry. So in all previous archaeological excavations, have objects of this material ever been unearthed?
Zhao: So far, there are no reports of silicified wood making decorations or other handicrafts in archaeological excavations in China. Therefore, although silicified wood has important scientific value in understanding the environment, climate, plant community and geological function in geological period, its archaeological significance is still unclear.
Q: The royal gardens in the Qing Dynasty and princes and nobles also regarded it as the treasure of private gardens and halls. Then how did this fossil enter the vision of ancient emperors?
Zhao: The formation of silicified wood usually takes tens or even hundreds of millions of years. Those silicified wood with high silicification degree, dense and tough texture, bright color, clear bark, knots, cavities and annual rings have the beauty of fossils, strange stones and jade, as well as the charm of primitive simplicity and nature, and are regarded as the essence of heaven, earth and mountains. Small ones can be carved into decorative pieces and playthings, big ones can be used as furnishings and ornamental objects, and some people can be used as evil spirits in town houses. As a result, silicified wood and its products can not only enter the study and hall of literati, but also be introduced into the royal gardens and private gardens of royalty and nobility, and are favored by them.
Q: As an authoritative expert in jade research, do you think silicified wood is qualified to enter the "jade family"?
Zhao: I think it may be because the silicified wood with high silicified degree, dense and tough texture and strong luster is fine as jade after processing and polishing, and the wood structure is clear, so these silicified wood materials are called "wood stone jade" and "tree jade". In fact, "wood-stone jade" belongs to jade material in a broad sense, which is different from "the beauty of stone, the man with five virtues" in China traditional culture. It is also different from nephrite represented by Hetian jade in many features, such as significant differences in mineral composition and structure.
Q: Is silicified wood collectible?
Zhao: High-quality silicified wood (or "wood stone jade" and "tree jade") often retains very clear wood grain, trees, bends, knots, cavities and other different colors, which are natural, simple, heavy, dignified and unique. Therefore, it is also called "three-dimensional painting" and "poem without words". This material can be used to make jewelry and toys, and can also be used for display and appreciation. In addition to scientific research value, there is no doubt that there is a high collection value.
Q: The concept of "wood stone jade" appears frequently in Tibetan circles, which puzzles many people. Can you explain what "wood and stone language" is?
Liu: Most of the so-called wood, stone and jade in the market are made of silicified wood. What is silicified wood? After a long geological period, the wood buried underground has been replaced and filled with silica, but the residual structure of wood remains. Gemological mineralogy calls this organic jade material silicified wood. Silicified wood is produced in Xinjiang, Gansu, Liaoning, Shanxi, Fujian, Jiangxi and other places in China, and is also produced in Cuba and European and American countries. Many museums at home and abroad often display silicified wood of different sizes, shapes and colors; Some silicified wood is processed into small carvings because of its bright color, strong luster, dense texture and clear wood structure.
Q: Colorful and various kinds of silicified wood are popular in the market, so how are they classified?
Liu: Generally, silicified wood can be divided into four types according to the existing state of silica: ordinary silicified wood, opal silicified wood, chalcedony silicified wood and agate silicified wood. Each mineral type can be divided into white, gray, black, blue, green and red according to the main color. Among them, opal silicified wood is the most striking, and it is often called "wood opal". Most of them appear in the center of wood rings. After filling opal, it is milky white and translucent, and after polishing, it presents a unique delicate and colorful wood grain, which is quite popular among people.
Q: If we abandon the general term "silicified wood", "wood stone jade" will easily draw people's attention to another completely different gem material, which is commonly known as "wood stone" in China's gem industry.
Liu: Yes. Wood-changed stone and silicified wood are two completely different materials: the former has nothing to do with "wood", but has a complete asbestos structure-similar to the texture of trees. For many years, China's arts and crafts circles have defined "wood stone" as a kind of primary asbestos ore body, which is filled with silica and presents parallel fiber structure of asbestos and looks like a tree-like plate. One of its outstanding features is the status quo reflection, which is similar to a cat's eye gem. Because of its color, the gemstone industry calls the yellow one tiger's eye stone and the blue one eagle's eye stone. High-quality wood-changed stones (tiger's eye stone and eagle's eye stone) are mainly produced in Africa and Brazil. Tiger's eye stone is often processed into ring faces and bracelet beads, which is a popular low-grade gem.
Q: Perhaps it was influenced by the jade culture craze that someone gave silicified wood such a fashionable name. Do you think this name is appropriate?
Liu: As far as the broad concept of jade is concerned, it is ok to call silicified wood that reaches the jade level "wood stone jade", but it is not "real jade", let alone beautiful jade. However, most of the popular "wood stone jade" in the market belongs to opal silicified wood (or wood opal). The meaning of "wood stone jade" is unclear and easily confused with wood stone, so I think this formulation is not conducive to the promotion of such products.