Conch pearls are rare and beautiful. They are often pink, with a unique optical effect known as flame structure. They come from the Queen Conch (Strombus gigas) which are found in the Caribbean Sea. They are not formed in the same way as other pearls, having no nacreous layers, so in the true sense of the word they aren’t really true pearls, but calcareous concretions. This doesn’t stop them being highly prized as valuable gems.
Although conch shells have been abundant in the Caribbean, pearls are only found in 1 out of every 10,000 gastropods. Add to this the fact that only 1 out of every 50,000 pearls is of really good quality and you can see why they are so rare and expensive. Fine pearl jewelry is made from many types of pearls but only very rarely is jewelry designed with conch pearls. Especially rare is a conch pearl necklace. They are exclusive gems of extremely high value.
The pearl colors correspond to the colors in the conch shell. They vary from cream and light pink through several shades of pink to dark pink, salmon, golden, orange and brown. The most highly valued color is an intense pink with a tinge of violet, followed by an intense salmon hue. Conch pearls fade or bleach when exposed to sunlight or other bright lights, so they should not be worn in bright sunlight, but worn in the evening. Fading color is irreversible.
Flame structure is caused by the arrangement of the aragonite crystals and fibrous crystals in the upper layers of the pearl. They frequently have different colors and are arranged in two directions. This arrangement produces, by reflection, an optical effect reminiscent of a cat’s eye. The flame structure varies in appearance according to the size of the aragonite crystals beneath the surface. It can be graded as “fine silk”, “silky”, “velvety”, “slightly flamed” and “strongly flamed”. The most highly valued is a surface that has an appearance similar to wet silk.
Truly round pearls are almost never found. The symmetrical oval shape is considered the most perfect shape for a conch pearl. Some conch pearls are shaped like a football or an egg or a capsule. Most conch pearls found have an irregular elongated shape. When round pink pearl necklaces are seen they are therefore not conch pearls but pink freshwater pearl necklaces.
Conch pearls have always been natural pearls, usually found by fishermen and divers who collect the Queen Conch for its meat. As the conch becomes rarer and more endangered, conch pearls would have become even harder to find. But a major scientific breakthrough was announced on November 4, 2009. Scientists in Florida announced that they have been able to produce cultured conch pearls. The process does not require sacrificing the gastropod in the process. They have had a 100% survival rate. This new process may save the Queen Conch from extinction and provide pearl lovers the world over a new supply of these fascinating gems to add to their collection of pearl jewelry.