Pearl Knowledge Centre
Understand pearl types, quality factors, common treatments, care methods, and how to judge a pearl that suits you.
Before you start
Pearl is an organic gemstone created by living organisms. Its beauty is not loud; it comes from the warm, layered glow formed by nacre, light, colour, and time. Many people look at size first when buying pearls, but value also depends on lustre, surface, shape, colour, nacre quality, and matching. This page is not designed to make pearl knowledge complicated. It is designed to help you buy with clarity and confidence.
Pearl types
Natural pearls and cultured pearls
Natural pearls form without human intervention inside molluscs and are extremely rare. Most pearls in the modern jewellery market are cultured pearls. Cultured pearls receive human assistance, but the nacre still grows naturally inside the mollusc.
Freshwater and saltwater pearls
Freshwater pearls are usually produced by freshwater mussels and offer a wide range of shapes, colours, and prices. Saltwater pearls are usually produced by marine molluscs, including Akoya, South Sea, and Tahitian varieties.
Akoya pearls
Akoya pearls are known for their fine lustre and classic round appearance. They are commonly seen in Japanese pearl jewellery and suit clients who prefer an elegant, clean, and timeless style.
South Sea pearls
South Sea pearls are usually larger with a soft, sophisticated lustre. Common colours include white, silver-white, and gold. They suit clients who prefer a bold, mature, and collectible look.
Tahitian pearls
Tahitian pearls are often called black pearls, but their colour is not only black. They may show grey, deep green, peacock, aubergine, and other rich overtones. Their style is distinctive, mysterious, and premium.
Quality factors
Size
Pearl size is usually measured in millimetres. Larger pearls are generally rarer, but price cannot be judged by size alone. Size must be considered together with lustre, surface, shape, colour, and nacre quality.
Shape
Common pearl shapes include round, near-round, oval, drop, button, and baroque. Round pearls are usually the most popular, but baroque pearls can also be very artistic and design-forward.
Surface
Surface finish is an important factor in pearl quality. Pearls may have small spots, bumps, texture, or natural growth marks. Completely flawless pearls are uncommon.
Lustre
Lustre is one of the most important aesthetic qualities of a pearl. Good lustre looks bright, sharp, and layered. Weak lustre can make a pearl look dull and lifeless.
Nacre
Nacre quality affects a pearl's lustre, durability, and overall feel. Pearls with good nacre usually look warmer, more dimensional, and more suitable for long-term wear and collecting.
Colour
Pearl colour includes body colour, overtone, and orient. Not every pearl shows strong overtone or orient. Whether a colour looks premium depends on whether it looks natural, harmonious, and flattering on the wearer.
Matching
Matching is mainly used for earrings, necklaces, and jewellery with multiple pearls. Good matching considers size, colour, lustre, shape, and surface coordination. The better the match, the more refined the overall piece looks.
Care and buying
Pearl treatments
Some pearls may be treated by bleaching, brightening, dyeing, or irradiation. Treatment does not necessarily mean a pearl is unwearable, but it is important to be clearly informed. Clients should know whether they are buying a natural colour, an optimised colour, or a dyed colour.
Pearl care
Pearls are organic gemstones with relatively low hardness and need gentle care. Avoid perfume, strong acids, chemicals, cleaning agents, and overly dry environments. After wearing, wipe gently with a soft cloth and store separately from harder gemstones such as diamonds and jadeite.
Buying pearl jewellery
When buying pearls, do not only look at the millimetre size. Also consider lustre, surface, shape, colour, nacre quality, matching, and whether the overall design suits you.
Understanding pearl price differences
Two pearls can look similar yet have very different prices. The difference usually comes from variety, size, lustre, surface, shape, colour, nacre quality, matching, setting craftsmanship, and supporting documentation.
Common misconceptions
Only looking at size
A large pearl is not automatically a good pearl. If the lustre is weak, the surface is poor, or the nacre quality is low, the overall value will also be affected.
Assuming all black pearls are naturally black
Some black pearls are naturally coloured, while others are dyed or treated to appear black. Check the description carefully when buying, and refer to a certificate if needed.
Thinking pearls cannot be worn daily
Pearls can be worn daily, but they need proper care. Avoid chemicals, perfume, and abrasion from hard objects. A simple clean after wearing can help preserve their beauty.
Testing pearls with destructive methods
We do not recommend clients test pearls by scraping, acid washing, burning, or other destructive methods. If you have doubts, consult a professional or a recognised testing laboratory.
Pearl glossary
- Lustre
- The shine and reflective quality of a pearl's surface. High lustre looks bright and mirror-like; low lustre looks dull.
- Nacre
- The layered substance a mollusc secretes to form a pearl. Thicker, finer nacre usually gives better lustre and durability.
- Overtone
- A subtle secondary colour that appears over a pearl's main body colour, such as pink, silver, or green.
- Orient
- A soft iridescent shimmer that moves across the pearl's surface as light changes.
- Matching
- How well pearls in a piece of jewellery match in size, colour, shape, lustre, and surface.
- Body colour
- The main base colour of a pearl, such as white, cream, black, or gold, before any overtone is considered.
- Surface
- The condition of a pearl's skin. Small marks, spots, or growth lines are common and natural; fewer noticeable marks are more valuable.
- Cultured pearl
- A pearl grown with human assistance inside a mollusc. The nacre forms naturally, but the process is started deliberately.
- Natural pearl
- A pearl that forms entirely without human intervention. These are very rare in the modern jewellery market.
- Baroque
- A pearl with a non-symmetrical or irregular shape. Baroque pearls are often valued for their artistic, unique character.
Pearls are not gemstones judged by size alone. A pearl worth choosing is evaluated by lustre, surface, shape, colour, nacre quality, matching, and overall wearing effect. We hope that when you buy pearls, you not only find them beautiful, but also understand why they are beautiful, whether they suit you, and how to care for them well.
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