Conch pearls are far more rare than the finest natural Akoya pearl, and therefor are considerably more expensive. The name conch "pearl" is somewhat of a misnomer because these "pearls" are not nacre encrusted foreign bodies like an actual oyster pearl, but instead are calcareous concretions that form in the animal's digestive tract, in much the same way that a human kidney stone, or bezoar stone (gall stone) would.
Conch Pearls (pronounced "konk") are created in the digestive tract of spiral shelled gastropods in the Strombidae family, that live in sea-grasses or sand substrate found in warmer tropical oceans. Several conch sea-snail species produce conch pearls, and some are 'dual purpose,' producing both gems and food.
There are no cultured equivalents for conch pearls, and these natural creations are extremely rare, taking as many as ten thousand conchs to located one conch pearl. Of those, perhaps one in ten are worthy of gem status. This may seem wastful, but because the conch is a food sourch, the discovery of a conch pearl is a bonus to the fisherman who normally hunt them.
Conch Pearl Color & 'Flame Structure'
Typical colors range from the classic magenta, pinkish-orange or salmon, to a rich brown, gold, yellow or white. The unique surface quality and chatoyancy of conch pearls is referred to as its "flame structure," describing the distinctive mottled surface pattern and characteristic flicker of light across the surface. This flame structure pattern can sometimes form an 'eye,' elevating its value.
Michael Zobel Conch Pearl Brooch (left)
Most conch pearls have an elongated, oval, or baroque shape, and near-round specimens are very rare. Conch pearls weigh significantly more than oyster pearls, with a specific gravity of 2.85; and unlike regular pearls, are sized by carat weight. Although conch pearls can be found over 10 carats, larger sizes (above 2 carats) of conch pearls are uncommon, with the average size being under 3 millimeters in diameter. Due to the high value of conch pearls, drilling and/or gluing should be avoided in the mounting, as this will devalue the pearl. Additionally, prolonged exposure to sunlight (ultraviolet light) can have a dulling and fading effect, and should be avoided.
The finest specimens come from the "queen conch" (Strombus gigas), native to the Caribbean, between South Florida (Key West, aka "Conch Republic") and the Caribbean islands of the Bahamas and Bermuda. The Strombus gigas queen conch is also commonly called caracol reina, caracol rosa, caracol rosado, caracol de pala, cobo, botuto, guarura, and pink conch.
S. gigas can grow to 12 inches in length, and is the largest mollusk native to North America. Other species that can produce conch pearls are the Horse Conch (Pleuroploca gigantea), and the Fighting Conch (Strombus pugilis) from the West Indies.
Overharvesting and pollution have greatly diminished conch populations, and as a result, fishing bans and resource management have further increased the scarcity of conch pearls. These are a collectable connoisseur's gem that can rival the intrinsic value of any faceted gemstone.
Chemical composition: CaCO3
Semi-Precious Stones