Tridacna Pearl

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Photo courtesy of Scott Papper, GIA GG, AJP, CM (NAJA), Global Gemology & Appraisals

Species:  Calcareous Concretion
Pearl Type:  Giant Clam (Natural)
​Mollusk:  Tridacna Gigas
Mohs Hardness:  5 to 6 out of 10
Color:  White to yellowish white, often with visible flame structure
RI:  1.530 to 1.685
Birefringence:  0.155 (Birefringence blink technique)
SR/DR/AGG:  AGG
Spectrum:  Not diagnostic
Fluorescence:  Variable
SG:  2.83 - 2.87

Tridacna pearl facts

Photo courtesy of Scott Papper, GIA GG, AJP, CM (NAJA), Global Gemology & Appraisals

Tridacna pearls are very rare, organic gems produced by the largest living bivalve mollusk from the Cardiidae family, known as the Tridacna gigas or Giant Clam.

Tridacna clams can live for up to 100 years, can grow as large as 4 feet across and weigh up to 440 pounds.

Natural Tridacna pearls are known for their porcelain-like white color, sometimes with beautiful flame patterning.

Tridacna clams can be found in the shallow waters of the Indo-Pacific, inhabiting coral reefs.

Previously the largest pearl in history was a Tridacna pearl known as The Pearl of Allah.  It was found off the coast of the Philippines in 1934.  It measures 9.4 inches long and weighs approximately 14 pounds!  This pearl was valued by the San Francisco Gem Laboratory at $40,000,000.00.

The record was broken in 2016 by another Tridacna pearl found in the Philippines.  This massive pearl measures over 2 feet long by 1 foot wide and weighs approximately 75 pounds!

Tridacna Pearl Gallery