Keshi pearls are solid nacre. So what? Well, the mollusk-produced nacre is why we buy pearls and the reason pearls are gems. Nacre is natural. Nacre is precious. Keshi pearls are not only pretty, they are one-hundred percent naturally precious nacre.
Keshi is the Japanese term for freshwater pearls produced without a nucleus or seed bead. How are freshwater pearls made without a seed bead? The production of pearls occurs by two general methods: bead-nucleated and non-bead nucleated. Keshi pearls are the latter. As such, a keshi pearl consists of solid nacre, with no foreign, less precious nucleating material inside.
Keshi pearls are often misspelled as ‘keishi’ pearls and further confused with the term ‘heishi,’ which are beads and not pearls at all. To further confuse the nomenclature, keshi pearls are often called ‘petal pearls’ or ‘cornflake pearls.’ These terms reflect the common approach of naming a pearl by a similarly shaped object.
Keshi pearls are most accurately described as non-nucleated second-harvest production. What this means is that a mollusk produces keshi pearls upon second and subsequent harvests. Because a mollusk is a living, producing organism, it produces plump pearls with no nucleating agent on its first production cycle. On later production, the mollusk is older and produces less nacre.
Pearls that emerge from the second harvest are thinner, flatter, grayer, and irregularly shaped, often concave. Subsequent harvests yield yet thinner, yet flatter, yet more irregularly shaped nacre until it is no longer useful as a pearl. And the mollusk–no longer commercially productive–goes out to stud, so to speak. All of this freshwater pearl production occurs mainly in China, the world’s largest commercial producer of freshwater pearls.
Because keshi pearls are thin, drilling holes for stringing can be a challenge. Like needle pearls, where the drill is important, keshi pearls depend on the quality of the drill. Center-drilled keshi pearls are most common, for the ease of a successful drill through the center of the petal shape.
It’s the top of keshi pearls that are the most challenging to drill, as there is but a whisper of nacre through which to drill a hole. For the same reason, keshi pearls are difficult, if not impossible, to set in the same way as a round pearl.
It is precisely the fragility, the thin concave shape, and drilling difficulty that make petal pearls so desirable. To call them a by-product of freshwater pearl production is a bit misleading. It is a mistake to think keshi pearls are less pricey than first-harvest pearls. Quite the opposite! Keshi pearls are relatively expensive, owing to the short production time the mollusk can produce such a delicate gem.
Looking less like lustrous cornflakes than white petals a mollusk labored like mad to make, keshi pearls are more appropriately called petal pearls. Let’s call these beauties by their magnificent rather than mundane name. Wouldn’t you agree?