South Sea Pearls

South Sea pearls are among the largest commercially harvested cultured pearls in the world. The world’s largest round South Sea pearl is 24mm in diameter.

South Sea pearls are cultured throughout the South Pacific in coastlines along Australia, Myanmar, Indonesia, the Philippines, the Cook Islands and Polynesia. These waters are the native habitat of large oysters known as the gold lipped or silver lipped oysters (Pinctada maxima) which can be nucleated with beads larger than any other saltwater oysters.

The average size of a South Sea pearl is 13 mm, with most harvests producing a range of sizes from 9 mm to 20 mm. The large sizes of these pearls are related to the larger sizes of the host organisms, their shell sizes, the large beads that are viable for implantation, and the warm waters in which they thrive. The warm waters and currents speed the oyster’s metabolism and allow them to grow at much faster rates than Japanese Akoya pearls which live in much colder waters.

South Sea pearls are valued primarily for their size, shape, luster, color, and surface nacre. Large round pearls are always highly prized and small increases in diameter can increase valuations substantially. The quality and thickness of the nacre is reflected in the luster which along with the color are the most important factors affecting the beauty and value of the pearls. A smooth surface free of any blemishes is always desirable but uncommon in normal cultivation. A small blemish near the apex where the pearl was attached to its host is common but not critical because most pearls need a drill hole anyway, and that spot is perfect for that.

The body color of South Sea pearls is judged the same way as other pearls. White and pinkish pearls usually command higher prices than yellowish or cream colored pearls. However, when the yellowish hues become dark enough to be considered golden, their valuations can equal or even surpass similarly sized pinkish white pearls. Moreover, gold pearls have enjoyed a resurgent popularity and their higher prices are a reflection of that status. The presence of overtones and iridescence is always desirable in pearls regardless of origin.

Currently, Indonesia is the most important producer of South Sea pearls in the 9-12mm range while Australia produces more of the larger sizes. Australia’s first pearl farm was established on the Northwest coast at Kuri Bay in the 1950’s. The larger sizes of the Australian pearls are related to the refined implantation techniques and the decades of experience along with ideal water temperatures and high densities of phytoplankton, which sustain and nourish the oysters.

Australia tends to produce silvery white pearls while the gold lipped oysters produce creamy, yellow, and golden pearls in the more tropical waters of Thailand, Indonesia, and the Philippines. In Indonesia, both silvery white and golden pearls are produced.

The Pinctada maxima oyster is the oyster used for cultivation and it can produce up to four pearls in its lifetime. Inserted at different times with a growth period ranging around two years, the organism can only grow one pearl at a time. However, host Pinctada maxima oysters are not easy to come across in the wild so before the implantation process can even begin, the host oysters need to be raised from hatchery born larvae. Starting with millions of larvae, only thousands survive the initial two year rearing process to grow large enough to become receptors of pearl nuclei. Before an oyster can even begin to grow a pearl around the inserted nucleus, two years have already elapsed.

The insertion process requires the skills of a highly trained technician that can insert the seed into the center of the oyster without killing it. The nucleus itself comes from the shell of the American Pigtoe mussel from the Mississippi river. This Mississippi oyster shell has been tried and tested throughout the world and is known to be the most viable seed and is used exclusively for this purpose. Adjacent to the seed and also in the middle of the oyster, the mantle tissue from a donor oyster is inserted to hopefully initiate the growth of a pearl sac. Mantle tissue forms around the edges of the oysters and it is this tissue that is responsible for the production of nacre. By placing this transplanted tissue around or adjacent to the seed, the cells will induce the production of nacre around the seed and create the intended pearl. After two years pearl can be retrieved and the process can be repeated with a larger seed every time but only three more times.

The color of the resulting pearl is a combination of the color of the host shells nacre color along with the DNA of the donated mantle tissue. So, if golden pearls are more valuable than white pearls, why not go for the golden colors only? When golden pearls are produced, a significant percentage of them always come out yellow. While golden pearls are the most valuable, the yellow ones are worth much less and the harvest always includes both colors. For this reason, some producers prefer to go for the silver white pearls where the production will be more uniform with a higher rate of success.

Mature oysters are reared in protected open ocean bays or areas not far from the shoreline for easier access. They attach themselves to the insides of specially designed cage frames submerged and connected to buoys and strung out in long lines or circles. This is the essence of the farm but the oysters do most of the work.

To see the value in this amazing collaboration between man and nature we only need to consider the lengthy production periods and the limited survival rates but there is much more. The nucleated pearls cannot simply be put in the ocean and left alone for two years. They need to be cleared and cleaned of barnacles and plant growth every two weeks. They also need to be guarded from poachers that can easily snatch entire cages or entire lines of cages. Indeed, the process is long and involved and can only succeed in remote areas with immaculate waters. Only 3-5% of cultivated pearls are ever of top quality. Diseases can kill the molluscs and typhoons can wreck havoc on farms. And, as labor costs continue to rise we can be sure that the production of every pearl represents real value. Pearl cultivation is a lengthy process that can never be automated. From the people cleaning the shells to the technicians inserting the nuclei to the specialists overseeing the entire production, pearl farming is a fascinating process that cannot flourish without expertise and patience and only in a pristine environment.

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Pearl jewelry

Loose pearls