A Tahitian Cultured Black Pearl is obtained by means of a grafting operation performed by the Pinctada Margaritifera, the "Black Lipped Oyster" of French Polynesia. The oyster that produces the Tahitian Black Pearl can grow up to 12 inches in diameter (and weigh 10 lbs), as opposed to 3 inches for the "Akoya" oyster that produces white pearls, therefore allowing a larger nucleus to be implanted.
Japanese Cultured Pearls, are originally associated with The Japanese Cultured Pearl Industry (like Akoya pearl, or Mikimoto pearl). Colors include white, cream, gold, and rose. The sizes are generally smaller than south sea pearls. Large sized pearls are rare.
Freshwater Cultured Pearls, are farmed in freshwater and grown in mussels, as well as oysters. The irritants and the oysters used in making freshwater pearls are smaller than saltwater pearls. Freshwater pearls cultivating technique usually produce twenty or more pearls in one oyster, and it only takes one and a half years to two years to harvest.
Saltwater Cultured Pearls, are farmed in saltwater, and grown in oysters. Only one pearl is grown per oyster. It need more than two years and a half to get a good harvest (it means the pearls already have thick nacre). That causes saltwater pearl farming are more expensive than freshwater pearl. The colors are white, cream, yellow, gold, silver, rose and black. Countries known as producer of saltwater pearl are Burma, Indonesia, Thailand, and Philippines in South East Asia; Australia and Tahiti in South Pacific, especially in Tahiti, you'll find the beautiful black pearls.
Keshi Pearls, are very small pearl byproduct of the pearl culturing process. If debris enters an oyster while it's open during the harvesting process, the oyster covers the debris with nacre, thus creating keshi pearls.
Mabe Pearls, are created when human attaches a plastic dome to the inside shell of an oyster, which reacts by covering the dome with nacre. When harvested the mabe is cut off from the shell, and the inside filled with plastic or other material, to give more weight, and the mother pearl are placed on the back of the mabe pearls.
