Pearls are for June

June is one of the few special months with three birthstones: pearl, alexandrite and moonstone.

Pearl is the most commonly recognized for June and is the only birthstone that is organic. Interesting fact ,,, nearly all pearls today are cultured.  At one time, cultured pearls were considered by many to be of low value and not natural.  Actually, it is thru the round pearl culturing process, discovered by Mikimoto in 1916, that set commercial success and demand for Akoya, Chinese freshwater, South Sea and Tahitian pearls. 

A cultured pearl can be either bead nucleated or tissue nucleated.  Akoya, South Sea, Tahitian and some higher-end Chinese Freshwater pearls fall into the bead nucleated category.  Tissue nucleated pearls are typically freeform or near-round shapes of lesser quality.

Each category of pearls have their own nuance, but generally, the culturing process starts from collecting wild “spat” (baby mollusks) and breeding wild adult mollusks in hatcheries.  When a mollusk reaches a specific size, technicians will slow the mollusk’s metabolic rate by moving them into slow moving cold water, which acts like a sedative. 

Nucleating (or implanting) a bead into the mollusk’s gonad is delicate surgery, but is quick. Along with a bead, a piece of mantle tissue is placed on top and then into the slit. This stimulates the development of a pearl sac and creates nacre (the luster part of a pearl).  The recovery and pearl-growth period can take months to years to create appropriate nacre thickness and quality for saleable pearls.  At harvest, South Sea and Tahitian mollusks can be re-nucleated with a larger bead 2-3 times.  Akoya mollusks are sacrificed at harvest.  It should be noted that no part of the mollusk is left to waste ... food, buttons, tiles, mother-of-pearl jewelry.  

Fun Fact: A significant number of American mollusk shells (from the Tennessee River) are exported to Asia and  fabricated into calibrated, round beads for the nucleation process.  No other bead source materials (wax, plastic, stone) has been successful for this process ... rejection or death of the mollusk occurred.  

Finally, Chinese freshwater pearls are tissue nucleated.  Tiny slits are made (as many as 15) on each side of the mollusk’s mantle tissue (the tissue lining the inside of the shell), where a 3mm piece of donor-tissue is placed into each slit.  The recovery time for this mollusk is very short. Harvest from this process: nearly 30 pearls!  The pearl growth time, however, starting from tissue only, is quite lengthy.

Growth periods:  Akoya, South Sea and Tahitian - 24 months; Chinese Freshwater - 3-5 years