Due to industry differences or different angles, people classify pearls in different ways. The general situation is as follows:
People are used to calling cultured pearls in seawater shellfish and cultured pearls in fresh water mussels. Because of this, people first divide pearls into seawater pearls and freshwater pearls because of different waters.
1. seawater pearl
According to different kinds of shellfish, seawater pearls can be divided into three types: seawater pearls (Pinctada martensii and Hepu pearls), Nanyang pearls and black pearls (Tahiti pearls).
(1) seawater pearl: commonly known as seawater pearl. The main producing areas are Japan, China, Viet Nam and Myanmar. Some experts in China call it "Hepu Pearl" because Hepu Pearl in Guangxi is also produced in Malpighia. The diameter of seawater beads is generally less than 10 mm, and it is difficult to produce large pearls because of their small size.
(2) Nanyang Pearl: It is produced in a white butterfly shell and grows in the so-called "Nanyang" waters with high water temperature, hence the name. Due to the large shellfish, the diameter of pearls produced is generally above10 mm. The main producing areas of Nanyang pearls are Australia, Indonesia, Philippines, Malaysia and Hainan Island in China.
(3) Black Pearl: The pearl is large in shape, with a diameter of more than 7mm, and is produced from the shell of a black butterfly. Because the living conditions of this kind of shell are similar to those of white butterfly shell, some experts classify it as "Nanyang pearl", which can be divided into white Nanyang pearl and black Nanyang pearl.
Black butterfly shells and white butterfly shells live in roughly the same place. However, only black butterflies in Polynesia and Seychelles are the darkest, so they are most suitable for producing black pearls. At present, only Tahiti in Polynesia produces black pearls. Because the local lagoon is most suitable for the survival of black butterflies, the pearls produced are black and shiny. Therefore, some people call black pearls "Tahiti pearls".
In addition, pearls occasionally grow in abalone and snail. Because of its gorgeous colors and rich colors, it is also very precious. Such cases are called abalone pearls and Fritillaria pearls according to their mother shells. These are all seawater pearls.
2. Freshwater pearls
Freshwater pearls are produced from mussels that grow in rivers and lakes. The most common species are Hyriopsis cumingii and mussel. Because these two kinds of mussels can grow for more than ten years, the size of pearls produced can range from 1mm to more than ten millimeters or even more than 20 millimeters.
According to the growth status of pearls in shellfish, some scholars divide them into three types: free pearls, enclosed pearls and polymerized pearls.
(1) Free pearls: pearls that grow in shellfish and are not attached to shells. This kind of pearl, regardless of its shape, is wrapped in nacre and is a complete pearl.
(2) Shelled pearls: pearls closely attached to shells. Therefore, one side of the bead adheres to the shell. Some people also call the grotesque pearls in this kind of pearls pictographic pearls, while the semi-circular pearls are called "semi-pearls" or translated into "marbi" according to foreign languages.
(3) Polymerized beads: two or more pearls are mixed together by an organic layer, a prismatic layer and a pearl layer; Or several millet beads are wrapped together to form a pearl ball.
In addition, some people in the pearl industry divide pearls into round beads, rice beads, steamed bread beads, ring beads and irregular beads according to their shapes.
There is also a pearl producing area in China, which can be divided into three categories: south, east and west. The so-called South Pearl, East Pearl and West Pearl. Historically, especially in the Qing dynasty, people called the seawater beads produced in Hepu "Nanzhu"; Freshwater pearls produced in Heilongjiang, Liaoning and other places are called "Oriental pearls"; Pearls produced in western countries are called "western pearls", and there is a saying that "Oriental pearls are not as good as southern pearls". However, in modern times, some people called the pearls made in Japan "Oriental Pearl" and said: "Oriental Pearl is not as good as South Pearl". In fact, the Japanese "East Pearl" here and the Hepu "South Pearl" in China belong to the same species, that is, the "seawater pearl" produced by Malpighian shellfish, and the quality of Japanese pearls is far better than that of Hepu pearls.
According to the different operation methods and the composition of the pearl core, cultured pearls can be divided into three types: nucleated pearls, seedless pearls and shelled pearls. Pearls are formed by secretions from the mantle of shellfish and mussels. In order to obtain pearls, people implant pearl nuclei with mantle cells into shellfish and mussels, and the pearls obtained have nuclei, so they are called nucleated pearls. The mantle cells are directly implanted into shellfish and mussels. With the growth process, the cells proliferate to form pearl sacs, and the pearls formed by secreting nacre are called seedless pearls. Pearl cores are mostly spheres made of shells, so nucleated pearls are mostly round beads, while seedless pearls are more difficult to form round beads.
For many years, only seawater pearls can be planted, but freshwater pearls can't. Therefore, seawater pearls are mostly round and expensive; The price of freshwater pearls is much lower. In recent years, Xie Shaohe, who graduated from Zhanjiang Fisheries College, has successfully cultivated freshwater nucleated pearls after more than ten years of research and experiments, and has formed commercial production.
According to the four elements of jewelry and jade, the international jewelry and jade industry divides pearls into two categories: "natural pearls" and "cultured pearls", and requires all cultured pearls to be marked with the word "cultured". In the early days, people were very modest. However, with the passage of time and the scarcity of natural pearls, people gradually get used to simply labeling "cultured pearls" with "pearls", and only when real natural pearls appear, do they deliberately label "natural". To this end, Mr. He Naihua, president of the World Pearl Association, has repeatedly suggested at international conferences that "cultured pearls" should be simply labeled as "pearls", and when natural pearls appear, they should be specially labeled as "natural". He further elaborated his reasons as follows.
(1) The formation process of cultured pearls and natural pearls is exactly the same, and the formation and growth of pearls is a natural development and growth process. This feature is different from any other artificial jewelry.
(2) Jewellery has a precedent-glass. People use "glass" to mark artificial varieties and "natural glass" to mark naturally formed glass.
(3) Shellfish and mussels sometimes produce "secretory beads" after surgery, which are called "SmithKline" by Japanese people and translated as "Tsui Hark" by some people. This is during the operation, the cells of the mantle rupture to form fragments, which are secreted to form pearls. The formation of "secretory beads" is related to manual operation on shellfish and mussels, but there are no artificial implants. In recent years, it has also been found that after pearls are taken out from cultured mother-of-pearl and mussels, so-called "regenerated" pearls may form again in the original pearl sac even if no foreign bodies are implanted. These secreted pearls and regenerated pearls can be counted as "cultured" pearls or classified as "natural" pearls. Many Japanese people are dubbed the word "nature" by Smith.
(4) It has become a common fact that almost all people in the world have adopted this method in their business operations. Some people of insight in the international pearl industry expressed their support for this proposal. Mr. Liang Shihua, an authority on jewelry in Hong Kong, even said humorously, "Just like giving IVF the title of' artificial' or' pregnant', it is neither necessary nor possible."
According to the Japanese, there were only "secretory beads" in the world jewelry teaching materials. From 65438 to 0983, Mr. He Naihua, who was stationed in Germany, first proposed and proved that freshwater pearls also have "secretory pearls" in the German jewelry industry, and this argument was recognized by German jewelry experts. 1995, Mr. He Naihua formally put forward this proposal on behalf of China at the General Assembly of the International Jewelry Federation held in Athens. Finally, the international jewelry industry acknowledged this statement. And revised the "Pearl Manual" stipulated by the organization. This modification has great economic significance for freshwater pearls, because "secretory pearls" are often traded as natural pearls, thus obtaining high prices.