Akoya Pearls
Bead-nucleated pearls, implanted with spherical beads carved out of natural shell. Probably the most popular cultured pearls which grow in Japan and China, although only the third most valuable commercially produced pearl. The cold water temperature allows the mussels to produce uniform pearls with a brilliant luster. The average size of a pearl is 6 – 7 mm. Colours: rose, silver, white, cream, gold, grey-blue. Akoya mussels are more difficult to farm than freshwater mollusks because of a higher mortality rate and natural disasters like typhoons. Akoya pearls are rounder than traditional freshwater pearls and higher valued as the Akoya oyster is the smallest farmed oyster. Akoya pearls are usually round, however, a certain percentage of baroque and keshi pearls is also produced.

South Sea Pearls
The most valuable cultured pearls today, grown in the warm waters of Australia, Indonesia, the Philippines, Myanmar and Thailand. Available in white, silver, pink, gold, cream. Native people dived 10 – 80 m deep for these pearls throughout the warm Pacific Ocean. Since the 16th and 17th century South Sea pearls developed a global demand. Since the 20th century, over 400 boats with approximately 3,500 divers operated in Australia alone. In the mid 1990’s, South Sea pearls became available in larger quantities so people could purchase these pearls worldwide. It takes between 20 to 24 months to grow a South Sea pearl, not regarding all the complications that can cause them to die. Natural oysters are mixed with the hatchery stock to keep the population healthy. 
South Sea pearls are available between 9 to 20 mm, and can be white, silver, pink, and gold. They are generally larger than other pearls and have a higher value.

Tahitian Pearls
Tahitian pearls are considered to be the second most valuable farmed pearls worldwide. Tahitian pearls grow in the Black Lipped Oyster, not directly cultivated in Tahiti, but mainly throughout the islands and atolls in the middle of the South Pacific Ocean, called French Polynesia (since 1880). Only 1 of 10,000 oysters produces a pearl, within 22 – 26 months. Therefore they cannot be mass produced. Tahitian pearl oysters quickly became depleted, nearly to extinction. Fortunately, after strict regulations by governments, oyster beds where created to repopulate. Therefore, in the mid 1960’s, Tahitian cultured pearls could be harvested again. Today French Polynesia supplies the world with the most perfect cultivated pearls. They are also farmed in the Cook Islands, the Micronesian Islands, Japan, Thailand and the Philippines. 
Black Tahitian Pearls are highly valued because of their rarity. Tahitian pearls typically have a naturally dark body colour, showing the colours black, creamy white, and blackish grey, silver, rose, blue, green, and aubergine / purple. 
Matching these pearls into a fine necklace is a great task which requires the comparison of thousands of loose pearls. 

Freshwater Pearls
Fresh water pearls are formed by mussels in lakes, rivers, ponds, and other freshwater bodies, especially in China and Japan. A large number of them are cultured in former rice fields in China.
A mussel can produce up to 40 pearls. Today freshwater mussel farming can produce large quantities. Within 3 – 7 years a mussel can produce pearls between 3 – 13 mm, with a 40% chance of getting round pearls. Natural un-dyed freshwater pearls come in the following colours: white, pink, peach, lavender, grey, yellow and cream. 

Freshwater Pearls Tahiti Pearls Screen Shot 2014-02-03 at 21.53.36akoya-pearl-grades