Cultured saltwater pearls can be divided into three major types—Akoya, Tahitian, and South Sea. Freshwater is also suitable for culturing pearls. All three types are equally fabulous and appreciated for different qualities, but, like many things, it always comes down to individual tastes. You may like one type of pearls and not another, or you may be like me—liking everything! What follows is a quick review of the three main types of cultured saltwater pearls.

Akoya Cultured Pearls
Here is another eternally popular pearl. The white-to-cream Akoya cultured pearl is the one that probably springs first to your mind. (The matching ease of Akoyas would be the other reason to use them in pearl bracelets and necklaces; more on that below.) These pearls are grown in the ocean and are usually quite small: 2mm to 11mm; average is 6 mm-7 mm).
Akoyas are harvested from the Akoya oyster or P fucata, the smallest of the saltwater pearl oysters and the primary animal used in fishing for saltwater pearls in Japan. They usually grow to 8cm to 13cm in diameter. The Akoya oyster can sometimes achieve multiple nucleations at one time, up to five. If you want a larger pearl, however, you insert only one bead.
Akoya was the first round cultured pearl (‘spherical’ is the term used in jewelry-trade lingo, but that’s a little misleading; a round pearl refers to one that is within just under 1mm thick and, shall we say, elliptical by comparison with the next fattest pearl). Akoyas are spherical approximately 70 to 80 percent of the time in a given crop. Typically white or off-white with rosé or green overtones, these pearls take eight months to two years to grow from the moment their bead nuclei are implanted, and they make for an ideal staple jewelry item – the classic, straight-up white akoya strand is the timing-is-everything necklace preferred by brides.
Tahitian Cultured Pearls
When you think of black pearls, you’re likely visualizing a peacock-blue-sheened Tahitian Because it is the brightness of that specific blue that the market looks for in a Tahitian cultured pearl, the hue of its surface can deviate from the peacock-blue-sheen of the Akoya and range from black to grey or even brown with blue, green and purple undertones and rosé, green or blue overtones. Marketed only since the early 1970s, Tahitians are prized for their exotically large size and colours, and its price tag — note that I did not say ‘affordable’ — reflects a relative scarcity.
Tahitian pearls are cultivated mostly in the South Pacific in a large saltwater mollusk known as the ‘black-lipped’ oyster, Pinctada margaritifera. These oysters are the largest pearl-producing oysters, or pearl mussels, capable of growing to 12 inches in diameter, weighing up to 11 lbs., and living for as long as 30 years. Pearls from these oysters can grow to a size of 8 – 14 mm in a growing period of about two years.
Tahitian cultured pearls tend to have good to excellent luster, and that is naturally compared with akoyas and particularly freshwater cultured pearls, which must be treated (usually bleached) to display their sheen. When they’re harvested, farmers wash Tahitians in fresh water, dry them, and lightly buff them, usually in a tumbler with the gems, along with ground salt and bamboo chips.
Many times over the years, P margaritifera can be nucleated — that is implanted with beads like this — but the first harvest produces the most optimal pearl. Unlike their much smaller Akoya cousins, only about half the time are Tahitian cultured pearls spherical. And so, finding the single pearl to make a pair, or 10 to make a necklace, can take several years. This is one reason why a matched strand of Tahitian cultured pearls is quite expensive. And yet, because they often come in less-than-perfect shapes, they are also used by many jewelers in pieces that feature a single pearl and become as beautiful and striking as a necklace costing tens of thousands of dollars.
South Sea Cultured Pearls
P. maxima, one of the largest mollusks in the world, produces the most magnificent pearl in the world – the South Sea cultured pearl, usually the largest cultured pearl on the market. And, like the pearl itself, the name of the pearl suggests its origin: the South Sea cultured pearl is grown in Australia, Indonesia, and the Philippines (where the gem is the national pearl). The majority of South Sea pearls are silver, white, or a rich and rare gold color. Farmers do not dye South Sea pearls after harvest, though some wholesale buyers might after export.
Unlike a freshwater pearl mollusk, P. maxima will accept only one nucleation at a time; but the oyster can be nucleated again and again, three times during its lifetime. A South Sea cultured pearl takes 20-24 months to grow, with a size of 13mm being the norm (some reach 15mm and larger) and a spherical pearl occurring in 10 percent to 30 percent of any given crop. Australia produces 60 percent of the supply of South Sea cultured pearls, although Indonesian farmers produce more of the gold variety than Australian farmers.
Freshwater Cultured Pearls
In contrast with the saltwater cousins, freshwater pearls are produced in a mollusk and not in an oyster, and, as you might have guessed, they are grown in ponds, lakes, and rivers, not in the sea. Today’s freshwater cultured pearls are largely produced in China, and the round, high-luster gems that are the norm today represent a quantum leap in quality from the inexpensive, soft, rice-krispie-shaped gems common to the freshwater crop of decades past. In fact, many in the industry now hold that today’s freshwater cultured pearls are as beautiful as saltwater cultured pearls. This is a long way from the farm-fresh freshwater pearl’s reputation of decades ago.
Freshwater pearls are cultured from mussels in the family Unionidae, mostly in China. The US also produces a share; however, there, the beads used to induce pearl growth worldwide are made from ground shells of mussels.
Although many freshwater pearls are nucleated – implanted – with a starter ‘bead,’ a separate donor mussel’s mantle tissue is used, so tissue-nucleated freshwater pearls are 100 percent nacre. This gives them a brilliant luster and a sturdy outer surface that won’t flake and peel to show the inner bead as some imitation pearls do. Pearls that were bead-nucleated and harvested before they had a chance to develop a substantial nacre coating are often no more than a nugget of hard bead, covered with a paper-thin layer of nacre that’s liable to flake and chip. Like snuffed-out candles, once pearls are destroyed, they can’t be polished back into life.
Each freshwater pearl-producing mussel can take up to half a dozen implants at a time. It usually takes 2-6 years for one to grow; the finished pearl is normally 4mm to 11mm, though definitely larger freshwater pearls exist – and those larger sizes may carry a bigger price tag. The vast majority of a crop of freshwater pearls is composed of button pearls (flat on one side) or oval pearls – about 60 percent, according to the latest information from the Gemological Institute of America. Only about 2 percent of the harvest is round, so only about 2 percent is limited to jewelry that demands symmetry. Baroque (no symmetry) and semi-baroque pearls generally account for the remainder of the crop. Yet, in the hands of a designer who knows what to do with such unique pearls, they, too, can create some astoundingly beautiful jewelry.
In terms of color, the freshwater cultured pearl offers a lot: everything from pastels such as cream, white, yellow, orange, and pink are common; universally flattering lavender pearls are reaping a renaissance of popularity today. Just remember that when choosing the color of your freshwater pearls, the wearer’s skin tone should be the most important factor, and you should keep in mind which color will flatter and not distract. Considering their abundance compared to other pearl types, freshwater pearls should be much more affordable; they could even allow you to purchase a few different color choices!
Conclusion
Cultured pearl jewelry is within reach of every taste and wallet. Investigate carefully, play your cards right, and whichever pearls you fall for, your love will stand you in good stead for a lifetime.