Pearls are unlike any other gem, the only one made by a living creature rather than dug from the earth. This guide is the overview: what a pearl actually is, the difference between cultured and natural, the main types, how to tell a real pearl, what makes one beautiful, and how to look after it. Each section links to a fuller guide.
A pearl is an organic gem grown inside an oyster or mussel, formed from layers of nacre around a tiny irritant. Almost every pearl sold today is cultured, meaning gently farmed, and cultured pearls are just as real as rare natural ones. Pearls come in several types and colours, they are prized above all for their lustre, and because they are soft they ask for a little gentle care.
What is a pearl?
A pearl is the one gem made by a living creature. It grows inside a mollusc, an oyster in the sea or a mussel in fresh water, when the animal coats a tiny irritant in smooth layers of a substance called nacre, the same material that lines the inside of the shell. Over months and years those layers build into a pearl, and it is the depth of that nacre that gives a pearl its soft, glowing lustre. Because a pearl is organic and mostly nacre, it is also soft compared with other gems, which is why it needs gentler handling than a diamond or a sapphire.
Cultured and natural pearls
Natural and cultured pearls form in exactly the same way, the difference is only how they begin. A natural pearl happens by chance, when an irritant drifts into a mollusc on its own, and these are extremely rare, historically only around one in ten thousand. A cultured pearl is helped along, with a pearl farmer gently placing the irritant inside, after which the mollusc grows the pearl naturally. Both are entirely real pearls, and nearly every pearl sold today is cultured. We use the word cultured in just the same way we do for cultured diamonds, a genuine pearl, simply given a helping hand to begin. Our guide to cultured vs natural pearls explains it in full.
The main types of pearls
Pearls come in several types, named mostly for where and how they grow. Freshwater pearls, grown in mussels, are the most common and affordable, in soft whites and pastel pinks and lavenders. Akoya pearls are the classic round, bright white saltwater pearl. South Sea pearls are the largest and most luxurious, in white and gold, and Tahitian pearls are the naturally dark ones, in grey, green and black. Baroque simply means an irregular, characterful shape rather than a round one. Our guide to the types of pearls covers each in detail.
Is it a real pearl?
When people ask whether a pearl is real, they usually mean is it a genuine pearl or an imitation made of glass or plastic, and a cultured pearl is very much a real pearl. There are a few simple ways to tell a real pearl from a fake, the best known being the tooth test: a real pearl feels slightly gritty against the edge of your tooth, while an imitation feels glassy and smooth. Our guide to how to tell if a pearl is real runs through the tests.
What makes a good pearl?
Pearls are judged on a handful of qualities, and one matters more than the rest.
Lustre is the most important quality in a pearl, the deep, mirror-like glow that comes from good, thick nacre. A pearl with strong lustre almost reflects your face. After lustre come the smoothness of the surface, how round or characterful the shape is, the colour, and the size, but a smaller pearl with beautiful lustre will always outshine a larger dull one. When choosing, follow the lustre first.
Caring for pearls
Because pearls are soft and porous, they need a little more care than harder gems, but the rules are simple. Put them on last, after perfume and cosmetics, and take them off first, wipe them with a soft, slightly damp cloth after wearing, and never soak them or put them in an ultrasonic cleaner. Our guide to caring for pearls has the full routine. Looked after simply, pearls last for generations.
From here you can follow any of the guides above. You will find cultured pearls set in solid gold across our pearl bracelets, pearl studs and pearl pendants.
