Pearl

The classic check is the tooth test, and it works because of how nacre is built. Rub the pearl gently along the biting edge of a front tooth: real nacre — those thousands of microscopic aragonite plates — feels faintly gritty or sandy, while imitation pearls made of coated glass or plastic feel perfectly smooth. Back it up with your eyes: a real pearl's luster seems to come from beneath the surface, its color shifts subtly as you roll it, and no two pearls on a genuine strand are perfectly identical in shape, tone or surface.

Other tells: real pearls feel cool when first picked up and warm slowly against the skin, and they are heavier than most plastic fakes. Around the drill hole, an imitation often shows a tell-tale flaking or peeling coating over glass, while a real pearl shows clean layers. What no home test can do is separate a natural pearl (formed without human help) from a cultured one (started around a grafted bead or tissue piece) — that distinction is internal and takes an X-ray at a gem lab, which is exactly what auction houses do.

Almost every pearl sold today is cultured — grown on pearl farms since the technique was commercialized in Japan in the early 1900s — and four families dominate. Akoya pearls, from small saltwater oysters mostly in Japan, are the classic: white to cream, sharply lustrous, typically 2–10 mm, the pearl of the traditional strand. Freshwater pearls, farmed mainly in China from mussels that can grow many pearls at once, are the affordable workhorse — enormous variety of shapes and pastel colors, historically less round, with quality rising fast.

Tahitian pearls, from the black-lipped oyster of French Polynesia, are the famous naturally dark pearls — grey to black body colors with green, aubergine or peacock overtones, no dye involved. South Sea pearls, from the largest pearl oysters in the waters of Australia, Indonesia and the Philippines, are the giants of the family: white, silver or richly golden, commonly 9–16 mm, with thick nacre from long growth — and priced accordingly at the top of the cultured market. Truly natural, un-farmed pearls still exist but are rarities that trade at auction, not at the jewelry counter.

The pearl's symbolism grew straight out of its nature: a flawless, glowing sphere that emerges finished from a humble shell. Across cultures it has stood for purity, innocence and wisdom — 'pearls of wisdom' preserves the old idea that something precious forms slowly around life's irritations — and for hidden worth, which is why calling a person 'a pearl' means they are a rare treasure. In many traditions pearls are also tied to the moon and water, and bridal pearls remain one of the most persistent wedding customs in jewelry.

The lore has a famous double edge: some traditions held pearls to be tears of joy from the heavens, others warned that pearls given at a wedding foretell tears — a superstition happily ignored by centuries of brides. History's showpiece story is Cleopatra reportedly dissolving a priceless pearl in vinegar and drinking it to win a wager with Mark Antony — the tale comes from Pliny the Elder and may be embellished, but it captures how pearls once ranked among the most valuable objects on Earth. As June's birthstone, the pearl carries the gentler reading: purity, loyalty and quiet wisdom. These meanings are cultural and spiritual tradition, not medical fact — a pearl treats nothing, but it means a great deal.

Luster is the first word in pearl value: a top pearl reflects light sharply, almost like a mirror in the highlights, while a chalky, dim surface sinks the price regardless of size. After luster come nacre thickness (thin-skinned pearls dull and wear through), surface cleanliness (fewer spots, wrinkles and pits), shape (perfectly round commands the premium; symmetrical drops next; baroque shapes charm at a discount), size (value climbs steeply with millimeters), and — for strands — how well the pearls match. Type sets the bracket: freshwater strands can cost tens of dollars, fine akoya hundreds to a few thousand, Tahitian and South Sea pieces from hundreds into five figures.

Natural pearls play in a different league entirely. Because nobody seeded them and X-rays can prove it, documented natural pearls — especially with royal or historic provenance, like La Peregrina, the 16th-century pearl later owned by Elizabeth Taylor — sell at auction for sums no cultured pearl approaches. For ordinary buyers the honest advice is the reverse of most gems: don't pay for the word 'pearl', pay for the nacre. A modest strand with sharp luster and thick nacre outlives and outshines a bigger strand of thin-skinned pearls at the same price.

Imitation pearls are everywhere and often honest about it: 'shell pearls' (coated mother-of-pearl beads), majorica-style glass pearls and coated plastics fill fashion jewelry. The tooth test catches nearly all of them — smooth means fake — and a loupe around the drill hole settles doubts: coatings chip and peel where real nacre shows layered structure. Uniformity is itself a warning; a strand of perfectly identical, perfectly round, perfectly flawless 'pearls' at a low price is imitation by definition, because real pearls vary.

The subtler questions are within real pearls. Cultured versus natural takes lab X-rays, as noted above. Dye and treatment matter too: some freshwater pearls are dyed black to mimic Tahitians (dye concentrates around drill holes and looks flat next to a Tahitian's shifting overtones), golden color can be enhanced, and most akoya are routinely bleached and pinked — an accepted trade practice. When money is serious, buy from sellers who state type, origin and treatment in writing; a real Tahitian or South Sea pearl of size is never accidentally cheap.

At Mohs 2.5–4.5, a pearl can be scratched by almost everything else in a jewelry box, and its nacre is attacked by acids and alcohol — which includes perfume, hairspray and cosmetics. The old rule says it all: pearls go on last and come off first. Put them on after your fragrance has dried, wipe them with a soft, slightly damp cloth after wearing to remove skin acids, and never clean them in an ultrasonic machine or with commercial jewelry dips.

Store pearls in their own soft pouch, away from harder gems, and don't seal them long-term in airtight plastic — nacre holds a little moisture and does best with air. Jewelers often add that pearls are meant to be worn: regular gentle wear does them no harm and keeps them from drying in a vault. Restring pearl strands every few years (knotted between pearls, so a break loses one, not all) and they will pass to the next generation still glowing — pearls are heirlooms precisely because the care is simple and the reward is long.