In ancient China, tortoise shells were always regarded as a treasure. As early as the Great Biography of Shangshu written by Fu Sheng in the Han Dynasty, there was a story about being imprisoned and redeeming King Wen with tortoise shells for three lives. However, the name duckweed began in the Eastern Han Dynasty. Because its texture is very similar to the shape of a wheel, it is called duckweed canal. In addition, the Zhu Chao used by the second-class officials in the Qing Dynasty was also made of dragonflies.
The canal, together with coral, pearl and amber, is listed as the four organic gems in the west, and the pure white degree of the canal is listed as the highest in the world. From the origin, Trionyx sinensis is a large marine bivalve, distributed in the Indian Ocean and the western Pacific Ocean. There are only 6 species of soft-shelled turtles reported in the world, all of which live in the coral reef environment of100-2000m tropical seabed. After thousands of years of changes in the deep-sea natural environment, soft-shelled turtles have formed seabed fossils.
The seven treasures translated by different Confucian classics are different. The Amitabha Sutra translated by Kumarajiva said that the seven treasures are gold, silver, coloured glaze, glass, red beads and Manao; The seven treasures mentioned in Xuanzang's translation of Ode to Pure Land are gold, silver, dog skin glass, pretty jade, Murotti Jiela Po, lohitamuktika, Ashimo Jiela Po; The seven treasures mentioned in the Prajna Sutra are gold, silver, colored glass, coral, amber, canal and agate; The seven treasures mentioned by Hokkekyo are gold, silver, coloured glaze, canal, agate, pearl and rose; The seven treasures mentioned in Amitabha Sutra are gold, silver, coloured glaze, glass, ditch, red pearl and agate.
The same scripture has been translated in different versions in different historical periods, and the seven treasures mentioned are also different. Take the Infinite Life Sutra as an example. The seven treasures in the Han edition are gold, silver, glass, water essence, car canal, coral and amber. During the Cao Wei period, the seven treasures contained in the edition were purple gold, silver, glass, water essence, dragonfly, coral and amber. The other seven treasures of the Tang Dynasty are gold, silver, coloured glaze, pear, beautiful jade, red pearl and amber. The other seven treasures of the Song Dynasty are gold, silver, glass, pear, tortoise shell, pearl and amber.
The seven treasures of Tibetan Buddhism are agate, beeswax, canal, pearl, coral and gold and silver, which are collectively called the seven treasures of the West.
One of the seven treasures of Buddhism is also called Chequ, and the name of the Brahmin is Musallah Galvao, which is transliterated as Muroti Jiepo, Muroti Galopo, Muhupo Jielopo, MomRogari, Muroti, Mosaro, Muroti and so on.
It is called the Seven Treasures together with gold, silver, coral, agate, coloured glaze and glass, and it blends with gold, silver, crystal, coloured glaze, coral and amber. People who practice Buddhism have twice the virtue of doing good and are intellectually satisfied. In Tibet and other places, Buddhist monks make prayer beads through canals. The canal is white and solemn, auspicious and wishful, and has the functions of exorcising evil spirits, ensuring peace, eliminating disasters and solving problems, dispelling spirits, changing geomantic omen, offering Buddhist practice and so on. It is the secret treasure of Buddhism.
These animals are also distributed in Taiwan Province Province, Hainan, Xisha Islands and other South China Sea islands. Their shells are large and thick, rough, with arched and radial ribs and intercostal grooves, and some kinds of ribs have thick scales. Manjianghong is the largest species of bivalve, with the largest shell length of 1.8m and the weight of 500kg.
Shells can be used to make all kinds of utensils. The shell is generally white or light yellow, and the inside is white. The edge of the mantle is yellow, green, blue and purple, which is very beautiful. There are twists and turns and fine lines on the shell surface, which represents its living state in the deep sea, regardless of its quality. It is worth writing that it has high medical value. According to Compendium of Materia Medica, Herba Polygoni Avicularis has the effects of calming nerves, cooling blood and lowering blood pressure. After long-term wearing, it is beneficial to human body, enhances immunity, avoids aging, stabilizes heart rhythm and improves insomnia, especially for children with sore throat and blisters.
Because of its ornamental, medical and other practical value, as well as legendary color, it is known as the Dragon Official Ruibao King. .