A Pearl is a hard object produced within the soft tissue (specifically the mantle) of a living shelled mollusc.
The ideal pearl is perfectly round and smooth, but many other shapes of pearls occur. The most valuable pearls occur spontaneously in the wild and are very rare. They are referred to as natural pearls. For many centuries the only way pearls were obtained was to find hundreds of pearl oysters (that live in the sea) or pearl mussels (that live in freshwater), open them, thus killing them, hence the main reason for why the pearls fetched such extraordinary prices in the past.
Cultured or farmed pearls from pearl oysters and freshwater mussels make up the majority of those that are currently sold. A cultured pearl is formed in a pearl farm, using human intervention as well as natural processes. The unique luster of pearls depends upon the reflection, refractions and diffraction of light from the translucent layers.
They display iridescence which is caused by the overlapping of successive layers which break up the light falling on its surface. The very best pearls have a metallic mirror-like luster, however pearls can be dyed (especially cultured freshwater pearls) yellow, green, blue, brown, pink, purple or black and be of natural colour such as green, purple, aubergine, blue, grey, silver or black – although natural black is extremely rare, frequently referred as Tahitian pearls due to the discovery of the black pearly oysters in Tahiti.
A gem testing laboratory can distinguish between natural and cultured pearls using gemmological X-ray equipment to examine the centre of a pearl, focussing on its growth rings.
Single, natural pearls are often sold as a collector's item, or set as centrepieces in unique jewellery. Very few matched strands of natural pearl exist and in 1917, jeweller Pierre Cartier purchased the Fifth Avenue mansion that is now the New York Cartier store in exchange for a matched, double strand of natural pearls that he had been collecting for years; valued at $1 million at the time. People have coveted natural pearls as symbols of wealth and status for thousands of years.
There are many different types of pearl and their individual attributes are listed below:
AKOYA: This type is most familiar to many jewellery customers. Japan and China both produce salt-water akoya cultured pearls.
SOUTH SEA: Australia, Indonesia, and the Philippines are leading sources of these salt-water cultured pearls.
TAHITIAN: Cultivated primarily around the islands of French Polynesia (the most familiar of these is Tahiti), these salt-water cultured pearls usually range from white to black.
FRESHWATER: These are usually cultured in freshwater lakes and ponds. They're produced in a wide range of sizes, shapes, and colours. China and the US are the leading sources.
The oldest ever recorded written mention of pearls is in 2206 BC by a Chinese Historian. Centuries after, the desire for natural pearls remained strong. Members of royal families as well as wealthy citizens in Asia and Europe treasured their natural pearls and passed them down in the generations. From those ancient times until discovery of the New World in 1492, some of the outstanding sources of natural pearls were the Persian Gulf, Ceylon (now Sri Lanka) and Chinese and European rivers and lakes.
During Christopher Columbus' third and fourth voyages to the New World in 1498 and 1502 respectively, his discovery of natural pearl sources in the present-day Venezuela and Panama waters, intensified demand in Europe. However, within a hundred years, these sources began to decline due to overfishing, pearl culturing and oil drilling. The first step towards pearl culturing occurred hundreds of years ago in China. Today, pearl culturing is diverse and happening in various countries around the world.