Pearl Specialist Mini Course
Introduction to Quahog Pearls
What are Quahog Pearls?
Quahog pearls are non-nacreous pearls comprised of fibrous aragonite and organic matter. These pearls grow in Mercenaria mercenaria, a hard saltwater clam native to the New England coast. This species, commonly called the quahog, has a deep purple inner lip. The shells and pearls from this clam were once a form of currency among Native Americans in the region.
Although farmers grow these clams in aquaculture, these natural pearls remain exceptionally rare. This is due in part to mechanized harvesting methods. This processing destroys almost all pearls that might exist in the shell, making quahog pearls even rarer. While about one in 5,000 shells produces a pearl, most of those that survive are poor quality or damaged.
Some pearls escape the mechanized shucking only to be steamed. Cooking the pearl can damage it, but some survive unscathed. As a result, most quahog pearls nowadays are found by unsuspecting restaurant patrons.
Quahog Pearl Buying Factors
The Four Cs of colored gemstone grading aren't the best way to evaluate either nacreous or non-nacreous pearl quality. Instead, the calcareous concretion's color, flame structure, luster, shape/symmetry, texture, and size determine quality.
Quahog pearls can exhibit a wide...
A geologist, environmental engineer and Caltech graduate, Addison’s interest in the mesmerizing and beautiful results of earth’s geological processes began in her elementary school’s environmental club. When she isn’t writing about gems and minerals, Addison spends winters studying ancient climates in Iceland and summers hiking the Colorado Rockies.
When you join the IGS community, you get trusted diamond & gemstone information when you need it.
Get started with the International Gem Society’s free guide to gemstone identification. Join our weekly newsletter & get a free copy of the Gem ID Checklist!