In China's west coast of Leizhou Peninsula of the South China Sea and the west coast of Hainan Island, especially in coastal waters cities  such as Danzhou, clinical high and Chengmai cities and counties, the growth of a kind known as the "rare gem" of a large pearl oyster –white lip shell.

White lip shell also known as maxima shell, which can be seen from the shell jewelry, but also called the pearl of the white lip shell. It is a tropical and subtropical marine bivalve, is the special pearl kind of the south sea of china.

White lip shell shape like a dish, it’s a great individual, the general body length of 25 centimeters to 28 centimeters, weight of 3 kg ~ 4 kg. According to records, the largest reach 32 centimeters in length by more than 5 kilograms of weight up to more than normal with the large family Pinctada martensii 25 times to 30 times, so it is the largest of a pearl oyster,

White lip shell is also the world's largest and most high-quality pearl. White lip shell is widely used in the fashion pearl jewelry. white lip shell, particularly in the South China Sea, Hainan Island, China's rich coastal resources. According to information on Hainan reserves about 90% of the total all kinds of pearl in white lip shell.

Out with the white lip shell cultured pearl shell, not only large particles, color is good, price is high, both precious ornaments, but also valuable medicinal herbs. But also in the international pearl market is also hot item. According to the information recorded in Hainan had used fertility white lip shell was cultivated large pearls, after more than a year and a half cultivation,

Harvested in 1981 had a high 19 mm, diameter 15.5 mm and weighs 6 grams, peach-shaped, silver-white large pearls, which is a pearl of China's largest at that time, known as "Pearl King."

Another company that had worked with the white lip shell cultivated the large pearls, in 1986, harvest a larger pearl is 30 mm × 25 mm, weight 15 grams, then known as China's "Pearl King of Kings."

In 1995, Hainan Province, Danzhou of the units in the waters near the town of Man, using white lip shell nurturing a group of large pearls set to go.

According to reports, was identified by the authority of the gemstone jewelry sector, 15% of the pearl to reach grade class Ⅰ criteria, 23% of the pearl to reach Grade Class Ⅱ standard.

It is assessed that these were top grade pearls in the top stars in the international market can be sold for 1000 U.S. dollars each or more, most times one bomb can also be sold for 200 U.S. dollars.

Therefore, the use white lip shell farming out of the most precious pearl is the treasure; it is an excellent export product.