Pearl Buying Guide 2026: Akoya, Freshwater, Tahitian and South Sea

The Four Types, and What Separates Them

Almost everything on the market is one of four cultured types, and knowing which you are looking at settles most of the price question before any grading talk begins.

Akoya are the classic white round pearls, farmed principally in Japan and China from a small saltwater oyster. They run roughly 6–9mm, and their reputation rests on sharp, mirror-like lustre rather than size. If you picture a strand of pearls, you are almost certainly picturing Akoya.

Freshwater pearls are farmed in mussels, overwhelmingly in China, and account for the great majority of pearls sold by volume. A single mussel can be nucleated many times over, which is why freshwater pearls are inexpensive. Older freshwater production was distinctly lumpy; modern bead-nucleated freshwater is round enough that the visual gap with Akoya has narrowed considerably, and the honest way to judge them now is on lustre rather than on category.

Tahitian pearls come from the black-lipped oyster across French Polynesia and neighbouring waters. They are naturally dark — not dyed, which matters — in greys, greens, aubergines and the peacock tones that command the strongest prices. They are large, commonly 8–14mm.

South Sea pearls, farmed around Australia, Indonesia and the Philippines, are the largest of the four at roughly 9–20mm, in white through deep gold. Their nacre is thick and their growth is slow, and they are priced accordingly.

A useful shorthand: freshwater competes on price, Akoya on lustre, Tahitian on colour, South Sea on size and nacre depth.

The Five Factors That Set the Price

Pearls have no universal grading standard in the way that diamonds have the 4Cs, and the letter grades you will see in shops — AAA, AA+ and so on — are set by the seller, not by an outside body. Two sellers' AAA are not comparable. What is comparable are the underlying factors, and you can assess all of them yourself.

Lustre is the one that matters most and the one shoppers most often overlook in favour of size. Hold the pearl under a point light source and look at the reflection. On a high-lustre pearl you can see the outline of the light — sometimes your own reflection — with sharp edges. On a poor one the reflection is a soft glow with no boundary. Lustre is a direct consequence of nacre quality and thickness, so it is also a proxy for durability.

Surface covers pits, bumps, ridges and blemishes. Perfectly clean pearls exist and cost what you would expect. Minor markings that disappear at arm's length are normal and are a reasonable place to save money.

Shape runs from perfectly round through off-round, drop, button, and baroque. Round is the most expensive because it is the least common. Baroque is not a defect — a well-matched baroque strand is a deliberate look and often better value than a mediocre round one.

Colour means body colour plus overtone, the secondary tint that floats above it. Rose overtone on white Akoya, peacock on Tahitian, and deep gold on South Sea all carry premiums. Dye is common on cheap freshwater and is usually detectable at the drill hole, where the colour concentrates.

Size compounds every other factor, because larger pearls take longer to grow and fail more often in the process. Price does not rise linearly with millimetres; it steepens sharply past about 10mm.

Nacre Thickness — the Factor You Cannot See on a Website

A bead-nucleated pearl is a shell bead with a coat of nacre over it. How thick that coat is determines whether the pearl still looks like a pearl in twenty years or whether the bead starts showing through at the drill hole.

This is the single biggest quality difference hiding behind two superficially similar Akoya strands. A pearl left in the water longer grows more nacre; farms under commercial pressure harvest sooner. Thin-nacre pearls can look acceptable when new and then dull, chalk, or blister as the surface wears.

You cannot judge it from a photograph, and few sellers volunteer it. What you can do is ask directly, look at the drill hole under magnification for any sign of a bead edge, and treat exceptional lustre as circumstantial evidence — it is difficult to get mirror lustre from a thin coat. Tahitian and South Sea pearls are less exposed to this problem because their growth cycles are longer by nature.

Matching, Stringing and the Parts Nobody Photographs

A strand is a manufactured object, not just a bag of pearls, and the assembly is where a lot of quiet quality lives.

Matching means the pearls agree with each other in colour, overtone, lustre and shape, and that any graduation in size is smooth. Poor matching is obvious once you know to look: one pearl slightly greyer than its neighbours, or a size step that jumps.

Knotting — a knot of silk between each pearl — does two jobs. It stops the pearls rubbing each other, and it limits a break to a single lost pearl. It is standard on good strands.

The clasp is where cost is most often cut. A strand sold as fine jewellery should have a clasp in the same metal class as its price suggests, with a secure mechanism rather than a spring ring that opens in a coat collar. It is also the easiest thing to upgrade later, so a good strand with a mediocre clasp is a fair negotiating position rather than a reason to walk away.

Wearing and Storing Them Without Ruining Them

Pearls are soft — around 2.5 to 4.5 on the Mohs scale, well below quartz, which is what most household dust is. They are also chemically vulnerable in a way that gemstones are not, because nacre is calcium carbonate and dissolves in acid.

The operative rule is last on, first off: pearls go on after perfume, hairspray, cosmetics and sunscreen, and come off before you take any of it off. Wipe them with a soft damp cloth after wearing to remove skin oils and perspiration, which are mildly acidic.

Store them flat, not hanging, so the silk does not stretch, and keep them away from harder jewellery that will scratch them. A soft pouch inside a box is right; a sealed plastic bag is not, because nacre needs some ambient humidity and will craze if it is kept bone dry for years. Never put pearls in an ultrasonic cleaner or a steam cleaner. For the general principles behind all of this, our guide to caring for fine jewellery covers the wider collection.

Where to Buy, and What a Fair Deal Looks Like

Pearls are unusually well suited to buying online, because the factors that matter are photographable — a seller who shows a strand under a point light source, at the drill hole, and against a neutral background is telling you most of what you need. Be more suspicious of soft, evenly lit studio photography, which flatters poor lustre.

Ask three questions of any seller: what type are these, what is the nacre thickness or growth period, and has any colour treatment been applied. A seller who answers all three plainly is worth dealing with. A seller who answers only in letter grades is selling you their own scale.

On budget, freshwater strands make a genuinely good first purchase and modern quality is far better than their reputation. Akoya is the natural step up for a classic white strand. Tahitian and South Sea are size-and-colour purchases and are where it pays to see the goods in person if you can.

For artisan and coloured-stone pieces alongside pearls, Ouros Jewels and JewelHalo both carry the sort of work that sits well with a pearl strand, and Italist lists designer pieces from Italian boutiques. Grading and treatment disclosure still apply wherever you buy.

The Short Version

Decide on type first — it fixes most of the price. Judge lustre before size, because lustre is what people actually see. Ask about nacre thickness and treat evasion as an answer. Insist on knotting. Buy the strand you will wear rather than the one you will store, because pearls do not reward storage either financially or physically. And handle them last on, first off, forever.

Frequently Asked Questions