Though a variety of oysters can produce pink pearls, it is the pearl produced by the conch (mostly by the Queen Conch, Strombus gigas) that is generally thought of when the term pink pearl is used.
A pink pearl from a conch is like a kidney stone and is not an actual pearl, being made of calciferious concretions. It is heavier than other pearls too.
Pink conch pearls are rare, and the estimation of finding a pink conch pearl is one in 10,000. Within those odds it is thought that only 10 percent to 20 percent are gem quality, and finding pearls that match is a rarity as well.
A flame-like shimmery appearance (called “flame structure”) occurs in conch pearls, more often in pink ones than any other conch pearl color. The flame structure comes from the way that the calcium is arranged.
Though white and brown are rarer colors, pink pearls are the most desired, specifically a salmon pink. It must be noted that conch pearl colors can fade over time, though it is not entirely clear as to why. A preventative measure is to wear pink pearls in the evening.
Size and Shape
Though they can be larger, a pink pearl is on average one-tenth of an inch in diameter or smaller.
The shape of the pink pearl is oval or baroque (irregular) in shape.
Pink pearls can be found off of Florida and in the Caribbean, in such places as the Bahamas.
Until recently the conch, being a sensitive creature was unable to be farmed. Now, a specific and non-fatal method for farming conchs for their pearls has been successfully developed