Introduction

• According to the Gemology Institute of America (GIA), mysterious chocolate pearls are actually black Tahitian pearls, which have been treated to alter their appearance. Researchers at the Institute tested a large sample of chocolate pearls and determined that their cultivators, the Ballerina Pearl Company, used bleaching techniques to alter the organic compounds in the black pearls, giving them their rare chocolate coloring.
  
  

Tahitian Black Pearls

• Chocolate pearls are derived from Tahitian black pearls. These black pearls come from the black pearl oyster, or Pinctada Margaritifera, which is exceptionally sensitive to climate and water-temperature changes and often rejects attempts to be artificially stimulated to create pearls. The process is a slow one with a high failure rate and ensures that Tahitian black pearls can never be mass-produced in the same ways that cultured white pearls are. This accounts for their rarity and value.
  
  

Cultivation of a Black Pearl

• Black pearl oysters are injected with what is called a shell bead nucleus, a kind of pearl template. The pearl, to protect itself from irritation and injury, begins secreting calcium carbonate to coat the template, which mixes with a compound called conchiolin, a hard substance similar to a hoof or horn. These two together form what is referred to as a nacre, whose unique combination of organic compounds creates the color and iridescence of the pearl. According to the GIA, these compounds are the same ones treated to create chocolate colors in the pearl.
  
  

From Black Pearl to Chocolate Pearl

• Once the black pearls are harvested, they are treated with bleaches that affect the organic compounds in the nacre. While the Ballerina Pearl Company did not disclose its exact methods, the GIA's research study surmised that "the alteration [in color] is indicative of a bleaching process, resulting in the "chocolate" colors." It later goes on to say that, "While the mechanism is not fully understood, this alteration may be responsible for the characteristic differences ..." Since the Ballerina Pearl Company, several other companies have begun producing bleached black pearls to meet the chocolate pearl demand. No company has been forthright about its process, assumedly to protect its profits.