conch "pearls," calcareous concretions produced by
the Queen conch mollusk, Strombus gigas, often
have a very attractive pink color that may be enhanced by a
characteristic silky-looking "flame structure" (figure 1).
As described by Stevenson and Kunz (1908, p. 279)) many
specimens "present a peculiar wavy appearance and a
sheen somewhat like watered silk, a result of the reflections
produced by the fibrous stellated structure." In
addition, some conch "pearls" show a smooth, shiny
porcelain-like luster that makes them very attractive.
Because they are nonnacreous, they cannot be considered
true pearls; consequently, the term pearl, comทonly used
in the trade to describe this material, appears here in
quotation marks. The name of the molluslz should be
pronounced "conk" and both spellings, conch and conk, are
found in the literature.