A pearl necklace can look convincing at first glance, particularly when it is new, bright and beautifully strung. If you are wondering how to tell if pearls are real, the answer is rarely one dramatic test. Genuine pearls reveal themselves through a combination of small, reassuring details: their surface, lustre, weight, drill holes and the way they feel in the hand.
For a piece bought to mark an anniversary, a wedding or a family milestone, certainty matters. The safest approach is to use gentle observations at home, then seek a professional opinion where the value or sentiment of the piece calls for it.
First, understand what “real” means
A real pearl is formed by a mollusc. It may be natural, created without human involvement, or cultured, formed with careful assistance from pearl farmers. Both are genuine pearls, and cultured pearls are the type most often used in fine pearl jewellery today.
Natural pearls are exceptionally rare and can be highly valuable, but rarity alone is not the measure of beauty. A well-matched strand of cultured Akoya, freshwater, Tahitian or South Sea pearls may have remarkable lustre and take years of patient cultivation. Imitation pearls, by contrast, are usually glass, plastic or shell beads coated to resemble nacre, the luminous material built up by a mollusc.
This distinction is useful when assessing an inherited piece. A cultured pearl necklace can be entirely authentic, even if it is not a natural pearl strand.
How to tell if pearls are real at home
Begin with close observation in good, natural light. Real pearls are organic gems, so even carefully matched examples are not always perfectly identical. Look for subtle variations in shape, overtone, size and surface. One pearl may have a tiny dimple, a faint ridge or a soft change in colour that gives the strand character.
Imitation pearls are often remarkably uniform. Their surfaces can appear too smooth, their colour may be flat, and each bead may look precisely like the next. That said, high-quality imitation pearls can be made very convincingly, while fine cultured pearls can be almost perfectly round. Treat this as a useful clue, not final proof.
Look closely at the lustre
Lustre is one of the loveliest and most revealing characteristics of a pearl. Genuine pearls tend to show depth: you may see a crisp reflection of a window, your hand or a nearby object, with a soft glow beneath the surface. The light seems to come from within rather than sitting on top.
A faux pearl often has a more painted or waxy shine. Its reflection may look blurred and its colour can seem uniform from every angle. Freshwater pearls may have a gentler lustre than Akoya pearls, so do not mistake a soft glow for a sign that they are imitation. Pearl type, quality and condition all make a difference.
Examine the drill holes
If the pearls are drilled, inspect the holes with a magnifying glass or your mobile phone camera. On a genuine pearl, the nacre should continue neatly to the edge of the drill hole. There may be slight natural texture around it, but it should not look as though a coating has been applied over a bead.
On imitation pearls, the coating can sometimes chip, peel or appear thin around the holes, exposing glass or plastic underneath. Discolouration, rough patches or flaking at the drill holes are particularly telling. Be gentle when inspecting older pearls, as nacre can be worn by years of perfume, hairspray and everyday use.
Feel their temperature and weight
Pearls generally feel cool when first held against the skin, then gradually warm. Glass imitation pearls can also feel cool, so this is not a conclusive test. Plastic imitation pearls, however, often feel warm almost immediately and noticeably light for their size.
A strand of genuine pearls usually has a pleasing, substantial feel, although the weight varies considerably. South Sea pearls are large and weighty; freshwater pearls can be lighter. Compare the weight only with similar-sized beads, and rely on it alongside the visual checks rather than on its own.
The tooth test - useful, but not essential
You may have heard that rubbing a pearl lightly against the edge of a front tooth can reveal whether it is real. Genuine nacre often feels slightly gritty or sandy, while an imitation pearl tends to feel smooth. This can be a useful traditional indication, but it is not definitive. Some coated beads have texture, and some genuine pearls feel smoother than expected.
There is also no need to test a pearl in this way if it is mounted in a treasured ring, an antique necklace or a piece you do not own. Avoid biting, scratching or rubbing pearls aggressively. Their surface is delicate, and a meaningful jewel deserves careful handling.
What not to do when testing pearls
Pearls are softer than many gemstones and easily marked. Never use a knife, pin or abrasive surface to scratch a pearl, and do not expose it to flame, chemicals or harsh cleaning solutions. Tests involving fire, acid or a hard scrape risk damaging the nacre and are not needed to reach a sensible conclusion.
Likewise, do not assume a metal clasp proves that a strand is genuine. Imitation pearls can be finished with precious-metal clasps, while genuine pearls may be restrung with a simple fitting. The clues need to be considered together.
Signs to look for in a pearl necklace or bracelet
A well-made pearl necklace may offer useful evidence beyond the pearls themselves. Traditionally knotted strands have a small knot between each pearl. These knots help prevent pearls from rubbing together and limit loss if the thread breaks. They are a sign of thoughtful construction, though not a guarantee of authenticity.
Check whether the pearls sit evenly on the thread and whether there is stretching, fraying or a gap near the clasp. Older strands often need restringing, especially if worn regularly. This does not mean the pearls are poor quality. It is simply part of caring for an organic gem that has been worn and loved.
For earrings, rings and pendants, inspect the setting instead. Genuine pearl jewellery is commonly mounted with a small peg and adhesive, carefully concealed within the pearl. A visible seam, mould line or peeling finish is more consistent with an imitation bead.
When an expert opinion is worth having
At-home checks are excellent for spotting obvious imitation pearls, but they cannot reliably distinguish every type of pearl or establish the value of an important piece. An expert can inspect nacre quality, surface condition, shape, matching, origin indicators and any treatments. In some cases, specialist testing may be needed to determine whether a pearl is natural or cultured.
Professional guidance is particularly worthwhile for inherited jewellery, pieces intended for insurance, a pearl strand offered at an unexpectedly low price, or pearls you are considering selling. A valuation should describe the item accurately and reflect its condition, materials and current market considerations.
At Robert Anthony Jewellers, carefully handled jewellery services and experienced advice can help you understand what you have, as well as care for it properly. A worn thread, loose pearl or tired clasp is often repairable, allowing a treasured piece to be enjoyed again.
Buying pearls with confidence
When buying new pearls, ask clear questions about the type of pearl, its size, shape, lustre and surface quality. A reputable jeweller should be comfortable explaining whether a piece is freshwater, Akoya, Tahitian or South Sea, and whether any colour has been treated. Natural colours can vary wonderfully, from classic white and cream to silver, peach, grey and deep peacock tones.
Consider the occasion as well as the specifications. A perfectly round, highly lustrous strand may suit a formal celebration, while baroque freshwater pearls offer an individual, contemporary feel. The best choice is not always the rarest or most expensive one. It is the piece that feels right for the person who will wear it, and that has been chosen with knowledge and care.
A genuine pearl rewards a closer look. Take your time, trust more than one clue, and let an expert examine any piece whose story, value or place in your family makes certainty especially meaningful.