Detailed data of shells (mollusk shells)

Shell (bèi ké) is the mantle of mollusks living near the water, and it is a kind of calcification secreted by a special gland cell of mollusks, which is used to protect the soft parts of the body. The main components of shells are 95% calcium carbonate and a small amount of shellfish.

Basic introduction Chinese name: Shell Kingdom: Animal Kingdom: mollusk distribution area: marine pinyin: bé iké Japanese: shell かぃがら pronunciation, meaning, introduction, types, academic use, commercial use, handicrafts, ornaments, pearls, shell pronunciation, pronunciation: bé iké. Meaning (1) Shell: the hard shell or soft shell of shellfish. (2) Shells: the shells of mollusks. (3) Shell: the shell of an oyster or a clam. (4) Gastropods or bivalves. The number, shape and structure of shells vary greatly, and some types are 1 spiral shells (such as snails, snails and abalone). Some species have two petaloid shells (such as mussels, clams and scallops); Some species have eight plate-like shells arranged in tiles (such as stone turtles); Some kinds of 1 shells are wrapped in the body (such as squid, squid); Some kinds of shells even completely degenerate (such as ship maggots). The main components of shells are 95% calcium carbonate and a small amount of shellfish. Generally can be divided into three layers. The outermost layer is dark brown cuticle (shell skin), which is thin and transparent and has the function of preventing carbonic acid erosion, and is composed of chitin secreted by the edge of the mantle; The middle layer is prismatic layer (crust), which is thick and consists of prismatic calcite secreted by the mantle edge. The outer layer and the middle layer can enlarge the area of the shell without increasing the thickness. The inner layer is the nacre (bottom layer), which is composed of phyllodes secreted by the whole surface of the mantle. It has a beautiful luster and can be thickened with the growth of the body. The main chemical composition of calcite and aragonite is CaCO 3. There are many concentric and annular growth lines on the outer layer of the shell, and the light and dark colors alternate, but they do not represent age; It is formed because the edge of the mantle can't continue to secrete for some reasons (lack of food, different seasons, reproductive period, etc.). ). Species: tiger shell, white jade shell, luminous shell, five-claw snail, mother pig snail, pearl shell, chaste snail, pond snail, seven-legged snail, pig ear shell, horseshoe snail, bighorn snail, river snail, phoenix snail, conch, cap snail, conch, pond snail, jade snail, octopus, quail snail and frog snail. Chrysanthemum clam, sunshine cherry clam, Pacific fox clam, angel wing seagull clam, Xiufeng clam, oil painting sea fan clam, solid color sea chrysanthemum clam, safflower snail, yellow snail, lamarckian snail, West African cherry clam, snow mountain snail, eye spot snail, white star snail, map snail, hundred-eyed snail, black star snail, golden snail, fox snail and mouse snail. Bulb-shaped Eriocheir sinensis, golden brown bullet snail, golden fist snail, lip-moistening snail, crystal snail, small loquat snail, swollen loquat snail, cock snail, Darkmouth snail, golden axe snail, Gu Mi snail, reticulate long nose snail, big red snail, snipe snail, long fist snail, long fragrant snail, biting snail, etc. Martin's long-nosed snail, Hei Chi snail, twisted snail, Dongfeng snail, left-handed snail, snail, Zan's ginkgo snail, thick-tumor snail, vase snail, flame Tang Guan snail, Taiwan Province jujube snail, cone snail, thin Tang Guan snail, sea rabbit snail, purple sleeve snail, Bao Ling snail, big round snail, purple snail and so on. Radiocarbon dating of academic shells is a common material sent to AMS laboratory for radiocarbon dating. A large part of shell materials sent to accelerator mass spectrometry laboratory for carbon 14 dating are mollusk shells. Radiocarbon dating of shells is not easy because there are many factors that lead to uncertain results. Willard Libby, an American physical chemist, is a pioneer in radiocarbon dating technology. He thinks that shells are the worst radioactive carbon dating materials. Shells can be divided into oceans, estuaries or rivers. AMS lab analysts need to know the types of shells they are analyzing to determine possible pollutants and ways to remove them. The carbon needed for the growth of shellfish is obtained from the biosphere. Scientific research shows that shellfish absorb organic carbon from the ocean or land plants, and inorganic carbon from seawater bicarbonate, atmospheric carbon dioxide or fresh water bicarbonate. Shells are deposited by calcium carbonate crystals, forming an organic matrix. The organic matrix is a kind of protein called sclerosing protein. This protein only constitutes a small part of the shell, so the sample needed for radiocarbon dating is the inorganic part. Although carbonate is inorganic, it can still be dated, because its formation needs to absorb carbon 14 from the biosphere. Carbonate often exists in the form of mineral aragonite in shells, although in some shells it is a mixture of aragonite and calcite, while other shells such as oyster shells are mainly calcite. Using the carbonate component of shells will cause some problems because it is easy to dissolve and can exchange isotopes or chemical components with its environment. When shells exchange carbon with acids in the surrounding soil, the carbon ratio of shells will change, and the radioactive carbon age will also change. This carbon exchange usually affects the outer layer of shells. On the other hand, recrystallization can even affect the inner layer of the shell. This phenomenon is accompanied by the transformation from aragonite to calcite, which will change the ratio of carbon 14. When shells exchange carbon with modern calcite, recrystallization usually occurs. Commercial handicrafts-Shells of shellfish such as clams. Some of them have pearl-like iridescent luster, so they are used in jewelry industry to make necklaces and clothing accessories (buttons, etc. ), even installed on jewelry, more used to make shell carvings, collages, inlaid handles, etc. Among all kinds of shells, Pinctada martensii in the Torres Strait in northern Australia, Pinctada Manila in the Philippines, Pinctada burma in Myanmar, Giant mussel and Queen mussel in the West Indies are the best. Humans have used shells for a long time. Neanderthals in Zhoukoudian, Beijing, began to make decorations with perforated shells, which should be the earliest decorations for human beings. Shells were also used as coins in ancient times. A century ago, the deep-sea pearl oyster was a symbol of luxury and splendor of European aristocrats. It has a charming luster and changing colors like pearls, but it also has colorful colors different from pearls. The colorful pearl shell that breeds pearls has never been ignored and buried for thousands of years. In the late Qing dynasty, mussels and other shellfish were polished into buttons and decorated on high-end clothes in Hangjiahu area. Shell carving has always been the most cherished beautiful friend of designers. Especially in the past two years, jewelry-grade shellfish ornaments have been more and more loved by people who like handsome and natural in our city. Mother-of-pearl is a natural material, so the color and texture of each piece are very unique, which meets the demand of more and more consumers for personalized jewelry. The processing of mother-of-pearl ornaments is very complicated. The original mother-of-pearl should be polished very carefully, cut accurately and inlaid according to the design requirements. After many processes, it can be made into pleasing shell ornaments. Shells can be divided into five classes: Gastropoda (including snails, snails), Cephalopoda (parrots, octopus), Polypoda, Crapoda (like ivory) and Bivalves (two kinds of shells). A small shell can also play a big role. Fan-shaped, spiral, large and small, with a little processing, or wearing, or hanging, you can escape the fate of being thrown away and show off on the wall and desktop. The large fan-shaped shells are completely decorated on the inner wall of the wooden bowl through a special process, which is more environmentally friendly to use. And if you put on a beautiful pearl, make a curtain and decorate it in front of the window, the home scene with Southeast Asian flavor will be presented immediately. If you put it by the sea, you will use it to listen to the sound of the sea, but it is very useful in a natural style home. Curtain buckles and small rings, shells can make your home show the scenery of Southeast Asia without modification. The small conch picked up by the sea is smooth, round and shiny, and the two are matched together to make the ring of curtain buckle, which is beautiful and extraordinary. When they are attached to the curtains at home, the curtains will also be contaminated with the flavor of Shanghai style. Make a set of tableware with shells. Forks and spoons, each with its own purpose, are very interesting to put on the dining table. Shells were also used as coins in ancient times. Jewelry (1) popular jewelry 1, popular: pursuing the commercialization of jewelry. Most of them are large-scale mechanized production and large-scale sales. 2, personalized fashion: the pursuit of artistic and personalized jewelry, only a small amount of production. Most of them are handmade and sold. 3, home accessories: the pursuit of comfortable accessories. 4。 Clothing Accessories: Pursuing the artistry and trend of accessories. 5。 Auto parts: Pursuing the artistry and trend of accessories. (2) Art ornaments 1, collection: exaggerated, not easy to wear, used for collection; 2, ornaments: used for display; 3. Wear: Artistic modeling ornaments that tend to be practical. Pearl Pearl is an ancient organic gem, which is produced in mollusks such as Pinctada and Pinctada. The calcium carbonate-containing mineral (aragonite) beads produced by endocrine function consist of a large number of tiny aragonite crystals. According to the research of geology and archaeology, there were pearls on the earth 200 million years ago.