What are Keshi Pearls?
In a cultured pearl farm, an oyster is nucleated with a piece of tissue and a bead. Out of this combination, a pearl sac is formed and the bead serves as the nucleus of the cultured pearl.
If the mollusk expels the bead, or the tissue piece and bead separate, nacre will not form around the bead, and the loose tissue piece might produce a Keshi pearl instead.
Keshis are all-natural because there is no nucleus inside – meaning the Keshi pearl is nothing but pure nacre. Because Keshis are made up of pure nacre, there is nothing to stop the reflection of light – making them extraordinarily lustrous.
Because Keshi pearls are formed without a nucleus, their shapes tend to be more baroque, with round Keshis being very rare. Other shapes include rice, oval, flat, and semi-round.
The word Keshi is actually Japanese for poppy seed, hence the nickname the “Poppy Seed Pearl”.
Mabe Pearls
Mabé cultured pearls grow in saltwater mussels and some oysters, forming on the inside of the shell, rather than in the mussel’s tissue.
Also called blister pearls, their size is determined by the size of the implant.
To culture a Mabe pearl, either a half-round plastic bead or piece of mantle tissue is glued on the inside lip of the host shell.
As the mussel secretes pearl nacre it forms a domed blister.
As with other cultured pearls, assessment criteria include luster, surface, and strength of color.
The most desirable color is white with pink undertones, but an increasing interest in dark, smoky, and blue colors has emerged.
Handle Mabé cultured pearls with care. Their thin nacreous layer can crack or be damaged by misuse.
Cultured Seed Pearls
Formed by the early, accidental dislocation of a cultured pearl, seed pearls are just that — seeds of cultured pearls that never fully form.
Cultured seed pearls are the melee diamonds of the pearl universe — meant to enhance, to ornament, and to mesmerize.
When clustered together to frame a sapphire, or laced liberally through the floral lines of a vintage-style brooch, cultured seed pearls add a regal, stately charm to any piece of jewelry they adorn.
These pearls range in size from 1.0mm to 3.5mm