The so-called wheel lines of natural turtle products can only be seen by observing the whole turtle shell, but as beads, no lines can be seen at all. You can see the lines inside by looking with a flashlight. Only by pressing powder can we let everyone see the wheel lines on the beads with the technology. The result of constant speculation by merchants is social misinformation, but everyone believes that truth is the criterion and the truth is upside down.

Second, look at the traces of mines.

Natural dragonflies are not beautiful in appearance and have many defects. The key is that it is easy to crack or produce uneven surface after long use. This is the result of natural weathering of shells after the death of living things, and it is not easy to happen because there is gum in the cockroach. Of course, there are perfect ones, but the price is more expensive. If you come across a perfect one with a low price, please identify it carefully. Artificial dragonflies are powder-pressed dragonflies, which are made by imitating the characteristics of dragonflies and using special techniques. The output is not large, but it is realistic and has few defects. Generally, they are sold to big brand jewelry institutions, with high prices and good quality.

Third, look at the color.

There are white, ivory, transparent materials and brown, and of course there are rare purple, pink, purplish red and even rarer blood dragonflies. Dragonflies have a bright appearance and a pearl-like surface; The fake turtle is made of white stone or broken shell powder or white stone powder with glue, which is flawless, dark and white, polished and shiny and unnatural. ?

Fourth, look at the proportion.

Generally speaking, natural Polygonum hydropiper has a certain proportion, the density is 2.70g/cm3, the hardness is generally 2.5-3 degrees, and some varieties can reach 4 degrees. In addition to observing whether the cockroach's texture is natural, you can also try to mourn its weight with your hands. If it feels light, it may be unnatural.

Extended data:

Main value

decorate

The shell is thick, the inner shell is white and smooth, and the outer shell is yellowish brown. The most essential part of the shell end can be used as beads and decorative gems after cutting and grinding. In Buddhism, Kuai is deeply loved by many masters and believers. Handbeads with beautiful colors can be worn on the body in addition to decoration.

Living habits

Trionyx sinensis is often associated with a large number of zooxanthellae. This unicellular algae can circulate in water chestnut and carry out photosynthesis, which provides abundant nutrition for water chestnut. There is a structure called vitreous at the edge of the mantle of cockroaches, which can gather light and make zooxanthellae multiply in large numbers. This special relationship between clams and algae is called reciprocal growth. In addition, they eat plankton. Meat is edible, and big shells can be used as water containers or raw materials for shell carving. Some dragonflies can produce pearls. Small shells can be fired with lime and can also be used for viewing. In some countries, pangolins and pangolins have been successfully farmed.

When the sea water flooded the sea, it opened its shell and stretched out the thick mantle edge for activities. Like other bivalves, dragonflies carry food through the sea water flowing through their bodies. But they not only eat in this way, but also have the ability to grow food in their own tissues. Insect yellow algae can make full use of the convenient conditions provided by the mantle to reproduce, such as space, light and phosphorus, nitrogen and carbon dioxide in metabolites; You can use zooxanthellae as food. The reason why it grows so huge is that it can get food from two aspects.

Baidu encyclopedia: dragonfly