Pearl of Lao Tzu

One time largest known pearl

The The Pearl of Allah was once considered the largest known pearl. The pearl was found in the Palawan sea, which surrounds the island of Palawan in the Philippines, and was found by a Filipino diver. It is not considered a gemstone pearl, but is instead known as a "clam pearl" or "Tridacna pearl" from a giant clam. It measures 24 centimeters in diameter (9.45 inches) and weighs 6.4 kilograms (14.2 lb).

While biologists would regard this object as a kind of pearl, gemologists regard it as a non nacreous pearl, lacking the iridescence of the pearls that come from saltwater pearl oysters and freshwater pearl mussels. Because of its great size, a giant clam can create a very large pearl, but not an iridescent, gemlike one. The Gemological Institute of America (GIA) and CIBJO now simply use the term "pearl" (or, where appropriate, the more descriptive term "non nacreous pearl") when referring to such items, rather than the term "calcareous concretion" and, under U. S. Federal Trade Commission rules, various mollusk pearls may be referred to as "pearls" without qualification. Gemologist Michael Steenrod in Colorado Springs has appraised the pearl at $60,000,000 (1982) and $93,000,000 (2007). Another 1982 appraisal, by Lee Sparrow who owned a gem laboratory and appraisal business in the Phelan Building in San Francisco, put the pearl at $42,000,000. In America, the pearl was exhibited at the Ripley's Believe It or Not! Odditorium in New York, valued at $35,000,000. The Palawan Princess, a five pound non nacreous pearl then considered the second largest, was offered at auction by Bonhams and Butterfields of Los Angeles on December 6, 2009. Estimated to fetch between $300,000 to $400,000, it passed unsold.