Perhaps the best-loved gems of all time, pearls—both natural and modern cultured pearls—occur in a wide variety of colours. The most familiar colours are white and cream (a light yellowish brown). Black, grey and silver are also fairly common, but the palette of pearl colours extends to every hue. The main colour, or bodycolour, is often modified by additional colours called overtones, which are typically pink (sometimes called rosé), green, purple or blue. Some pearls also show the iridescent phenomenon known as orient.
Cultured pearls are popular for bead necklaces and bracelets, or mounted in solitaires, pairs or clusters for use in earrings, rings and pendants. Larger pearls with unusual shapes are popular with creative jewellery designers.
Pearl—natural or cultured—is the birthstone for June, together with alexandrite and moonstone.
Natural Pearls vs. Cultured PearlsNatural Pearls
Natural pearls form in the bodies, or mantle tissue, of certain molluscs, usually around a microscopic irritant, and always without human help of any kind.Cultured Pearls
The growth of cultured pearls requires human intervention and care. Today, most of the molluscs used in the culturing process are raised specifically for that purpose, although some wild molluscs are still collected and used.
To begin the process, a skilled technician takes mantle tissue from a sacrificed mollusc of the same species and inserts a shell bead along with a small piece of mantle tissue into a host mollusc’s gonad, or several pieces of mantle tissue without beads into a host mollusc’s mantle. If a bead is used, the mantle tissue grows and forms a sac around it and secretes nacre inward and onto the bead to eventually form a cultured pearl. If no bead is used, nacre forms around the individual implanted mantle tissue pieces. Workers tend the molluscs until the cultured pearls are harvested.
There are four major types of cultured whole pearls:Akoya Cultured Pearls
Akoya cultured pearls are the most familiar type of saltwater cultured pearl to people in the US and other western markets. Many customers think of white or cream coloured akoyas as the classic pearl used for jewellery, especially single-strand necklaces. Japan and China both produce akoya cultured pearls.South Sea cultured pearls
Australia, Indonesia and the Philippines are leading sources of these saltwater cultured pearls. South Sea cultured pearls can be white to silver or golden, depending on the type of oyster. Their large size and thick nacre, due to a long growth period, plus their limited critical growing conditions are all factors contributing to their value.Tahitian Cultured Pearls
Cultivated primarily around the islands of French Polynesia (the most familiar of these is Tahiti). These saltwater cultured pearls, sometimes referred to as black pearls, have a wide colour range. They might be grey, black or brown, and they can have blue, green, purple or pink overtones.Freshwater Cultured Pearls
Freshwater cultured pearls are the most commonly produced pearls and they are one of the most popular pearl types among shoppers and jewellery designers. This is due to their remarkable range of sizes, shapes and colours, plus their commercial availability at lower price points. They are usually cultured in freshwater lakes and ponds, often with many pearls grown in one oyster. China is the leading source for freshwater cultured pearls.