In the 1870's, three Japanese pioneers, working separately, began to unlock the secret of why oysters created pearls. After nearly 30 years of experimentation, the farmed production of pearls began, based on the insertion of a mother-of-pearl nucleus into the small native Akoya oysters. Once implanted, the oyster created the pearl, by laying down successive complex organic and crystalline layers, known as nacre, around a spherical mother-of-pearl nucleus. This became known as a Cultured Pearl, or Akoya Pearl, and the increasing commercial production was a contributory factor in the collapse of the natural pearl trade.
The small Japanese Akoya oyster creates a range of sizes of pearls from 5mm to a maximum of 9/10mm, and the Japanese long experience has kept them at the forefront of the pearl industry. Much of this knowledge has been exported to other pearl producing areas of the world, particularly in the creation of the large South Seas pearls.
Unfortunately for the Japanese pearl farmers, environmental difficulties, including the deteriorating quality of coastal seawater have coincided with the advances in production of the round Chinese non-nucleated freshwater pearls, whose increased quality and lower costs have projected them to be the rising stars of the pearl trade.