The so-called "Conch Pearls" (pronounced "konk") are produced by the Queen conch mollusc, which is found mainly in the Caribbean near Southern Florida. Technically a conch pearl is not a cultured pearl at all. It contains no nacre. The gems are calcareous concretions, similar to kidney stones.
A technique for culturing conch pearls has not been invented yet, so each and every one of those pearls is a natural pearl.Therefore, they are extremely rare and valuable.It is estimated that only one in 10,000 conchs produces a pearl and that less than 10 percent of those are of gem quality.
Conch pearls are discovered by fishermen, since the meat of the Queen conch is valued as food. So actually the conch pearl is an acceptable gift, a by-product, harvested as the fishermen clean their catch.
Usually Conch pearls are small in size - 3 millimetres or less - and baroque or oval in shape, the colours range from pink, yellow, brown, white, or golden. A salmon-coloured orange-pink shade is much sought-after. White and brown are rare.
In addition to their colourful appearance, the Conch pearls may show an attractive surface feature called "flame structure," a unique pattern in the colouration.The flame structure is mostly found in the pink or white-pink pearls, although the other colours sometimes also exhibit it.
Unfortunately the vivid colours of the Conch pearl tend to fade significantly over time. A scientific explanation is yet to be delivered, but it is assumed that sunlight is responsible for the loss of colour.Therefore it is recommended not to expose Conch pearls to excessive sunlight.
Since conch pearls are naturally both rare and unique, finding matching pearls for sets, earrings, strands, etc., is extremely difficult. A set of matching Conch pearls will be of increased cost and value.