The magic secret of the pearl is a mystery of origins. Believed to reflect the soul of an oyster, a natural pearl is an accident of nature, formed when an irritant – such as a parasite or a piece of debris – causes the mollusc to secrete a fluid that coats the invader. This irritant forms the nucleus of the pearl, then layer upon layer of the coating, known ‘nacre’, is deposited on the irritant until a lustrous pearl is formed.

A cultured pearl undergoes the same process. The only difference is that the irritant is a relatively large, surgically-implanted bead, placed in the body of the host oyster to stimulate pearl formation. Once the irritant is in place, it can take up to three years for the pearl to reach its full size. As long as there are enough layers of nacre to result in a gem-quality pearl, the size of the nucleus is of no importance to its beauty or durability. Pearls can come from either salt or freshwater sources and, typically, saltwater pearls tend to be of a higher quality.

The farms within the clean waters around Bali, Lombok and Raja Ampat are yielding beautiful, high quality South Sea pearls that are exported all over the world. When purchasing, you will find that the quality of the sheen and radiance of the pearl, known as the lustre, is not difficult to evaluate. Pearls with high lustre will sharply reflect the images around them, shining with a metallic three-dimensional glow and a subtle display of different surface colours. Low-luster pearls look dull with little or no reflectivity. Nacre is the most important feature in the appearance and durability of the pearl; it should always be at least 0.35 mm thick. If you can see the bead through the nacre or if it is split, peeling or patchy, it is a very low grade pearl; check especially for cracking around the drill hole. A fake pearl can be detected by biting on it; an imitation pearl will glide across your teeth, while the layers of nacre on a real pearl will feel chalky and gritty.

If you’re on a SeaTrek Sailing Adventure to Raja Ampat, the schedule might include a visit to the Cendanda Pearl Farm at Alyui Bay, one of the larger producers of high quality seawater pearls in the region. Alternatively, if you’re on a Komodo cruise, strings of inexpensive Lombok pearls are available from the Komodo vendors.