Keshi Pearls: What They Are and How They Form

A keshi is a cultured pearl that grew without a bead in an oyster farmed for bead-cultured pearls.¹ CIBJO’s term for it is a keshi cultured pearl.

How keshi pearls form#

Keshi form as a by-product of pearl culturing. A pearl sac can grow from an injury to the mantle during handling, from part of the grafted tissue, or from the whole graft after the oyster rejects its bead, and the sac then makes a pearl with no bead.¹

Keshi used to be seen mostly as by-products, but today they are also grown on purpose on pearl farms.⁶ Either way they are cultured, not natural: CIBJO defines them as forming, accidentally or on purpose, through human intervention.¹

Where keshi pearls come from#

Keshi come from the same oysters as bead-cultured pearls: the Akoya oyster, Pinctada maxima, the black-lipped Pinctada margaritifera and Pinctada radiata. CIBJO gives the main ones their own names, Akoya keshi, South Sea keshi and Tahitian keshi cultured pearls.¹

The first keshi were small, near-round nacreous pearls from Japanese Akoya oysters, usually about 2 mm or smaller.³ The term was later applied to large beadless cultured pearls formed in the gonads of South Sea and Tahitian oysters.⁵

The term covers marine pearl oysters only. Similar by-products of freshwater culture in the United States are called Lagniappe cultured pearls, from a word used in southern Louisiana for a little bonus.¹

Keshi sizes, shapes and colors#

Keshi range from under 1 mm to 16 mm (larger ones are very rare)⁴. Keshi from the large South Sea oyster are bigger than the original Akoya keshi.⁴

Their shapes are baroque, button, oval and drop¹. CIBJO describes keshi as essentially baroque, and SSEF found perfectly round ones rare.^{1 5} The page baroque pearls explains the shape. In a 2026 GIA study of 43 South Sea keshi from an Australian farm, most were button-shaped, with a flat or concave base.⁶

CIBJO describes their colors as white to yellow and gray to black¹.

Why keshi are mostly solid nacre#

With no bead inside, keshi are mainly composed of solid nacre, like natural pearls.² Some South Sea and Tahitian keshi are hollow or contain a lot of organic matter.¹

How labs identify keshi pearls#

Telling keshi from natural pearls can be hard. X-ray imaging shows organic-rich centers, voids or lines instead of a bead, and because some of these features also occur in natural pearls, a few results are inconclusive.² GIA’s 2026 study found that the internal features of some South Sea keshi closely resemble those of natural pearls.⁶

The difference matters for value. In 2010, SSEF warned that beadless cultured pearls from South Sea oysters, some sold with reports calling them natural, were entering the natural pearl trade, and that some traders were picking out the ones with the most confusing internal structures.⁵ Most keshi are believed to grow in the oyster’s gonad, while natural pearls form mainly in the mantle.⁶

What to call keshi pearls#

Because the word has been misused, CIBJO says “keshi” should always be qualified, as in “keshi cultured pearl”.¹ SSEF writes “beadless cultured pearl” on its reports instead,⁵ and GIA’s reports don’t use the word either.² GIA’s research articles call them non-bead cultured pearls. In the United States, any cultured pearl must be described as “cultured” whenever the word “pearl” is used.⁷