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Things
are not always as they seem. This is especially true for the conch “pearl" and
the melo melo “pearl," two types of gemstones that aren’t really pearls at all.
Confusing? Yes, as these “pearls" resemble true pearls in more ways than one. Both
the melo melo and the conch “pearl" are rare natural gems produced in marine
animals are referred to as pearls look like pearls, and are used to create
beautiful jewelry. So why aren’t they pearls? And if they aren’t true pearls
than what the heck are they?
Non-nacreous
pearls
Interestingly,
not all “pearls" are made of nacre, the combination of aragonite (calcium
carbonate) and conchiolin that is secreted from a mollusk and layered together to
form what scientists call a nacreous pearl. Some marine animals, like the Queen
conch and the melo melo sea snail, produce gorgeous gems made up of non-nacreous
calcium carbonate. Calcite, rather than aragonite, is the primary material here.
(This material, by the way, is said to be similar to the stuff that produces
kidney stones in humans.)
Because
they are non-nacreous, the conch “pearl" and the melo melo “pearl" are not
considered true pearls by gemologists. Instead, they are classified as
calcareous concretions and referred to as “pearls." Note the quotation marks
surrounding the word “pearl." This punctuation is used to signify that the gem
is not a true, nacreous pearl.
Conch
“pearls"
Conch
“pearls" are natural gems found in the Queen conch, Strombus gigas, a
beautiful marine animal prized for its gorgeous shell and succulent meat. (Walk
into any popular Caribbean eatery and you’re likely to find a selection of conch chowder and
conch fritters on the menu. Note: Make sure to pronounce it correctly: conk, or
you might get conched over the head.) The official symbol of the Bahamas and the Florida Keys, the Queen conch is fished in the
warm, shallow waters of the Caribbean where it lives. The “pearls" are a delightful byproduct
found by fisherman when the meat and shell are harvested.
Typically
oval or baroque and less than 3mm in diameter—although much larger ones can be
found—the porcelain-shiny conch “pearls" display the same colors as can be found
on the animal’s shell interior: white, tan, yellow, and pink. A lovely shade of
salmon-pink is the most popular color and typically commands the highest price.
A notable
characteristic of conch “pearls," but one that not all specimens display, is
flaming, or chatoyancy. Described as a silk-like or wet silk appearance
and typically only present on the pink “pearls," flaming occurs because of the
way the “pearl’s" layers are structured. Unlike pearls formed with nacreous
crystals, conch “pearls" are formed by concentric layers of fibrous crystals.
The flame effect is an optical illusion that results from this layered arrangement.
A highly desirable trait, flame structure on a “pearl" will command more money
than a “pearl" without this trait.
Like real
pearls, conch “pearls" are thought to be produced by the animal as a protective
measure against an intruder. Attempts to culture conch pearls, however, have
been unsuccessful, although many efforts are underway.
Due to
historical overfishing, the Queen conch is now protected in the Florida Keys, although the animal is fished in
other parts of the Caribbean. When harvested, the Queen conch does not always contain a “pearl"
in fact such “pearls" are extremely rare. According to the Gemological
Institute of America, only one in 10,000 Queen conch shells contains a “pearl"
adding to their appeal, very few of these are gem quality.
A
relative newcomer to the world of decorative jewelry, the conch “pearl" was very
much in fashion in Victorian-era baubles, but fell out of favor for a while.
Today, conch “pearls" are again enjoying a surge in popularity. Anyone interested
in purchasing jewelry made with a conch “pearl" should be aware that the color
of these gems fades over time. While scientists are unsure why, some postulate
that it has to do with ultraviolet rays breaking down the natural pigments,
although even in dark places, the gems will eventually fade. Heat, age and
dehydration are also thought to factor into the “pearls’" fading. Conch
“pearls" should be worn only occasionally, and it is advisable to limit their
time in the sun.
Melo
Melo “pearls"
The South China Sea, the Pilippines, India and the Andaman Sea are home to a big orangey-brown
gastropod called the melo melo sea snail. Like the Queen conch, this beautiful marine
animal with its oversize scrolled shell can produce colorful non-nacreous
“pearls."
Ranging
in color from tan to yellow to orange, these very rare calcareous concretions
are mostly spherical and typically quite large. (It’s theorized that the
animal’s ability to produce “pearls" of such substantial sizes is due to its wide
shell opening. In fact, one notable melo melo “pearl" weighed in at 397.52
carats and was said to be nearly the size of a golf ball.) The coveted orange-colored
melo melo “pearl" can exhibit intense flame structure, a highly desirable
trait, although, like the conch “pearls," the brilliant color will fade over
time.
According
to the Gemological Institute of America, as in nacreous pearl formation, the
very rare melo melo “pearl" is most likely the result of an intruder…in this
case believed to be formed when the gastropod’s large “foot" is bothered by an irritant.
Scientists aren’t completely convinced of this theory, however.
Fashionable
among Asians, melo melos are only now being appreciated by Western cultures. Like
conch “pearls," attempts to culture melo melo gems have been unsuccessful, thus,
like conch “pearls," the melo melo “pearls" on the market are rare and natural,
and of course, expensive.
A graduate of the Gemological Institute of America’s Graduate
Pearls program, Amy Drescher is a fashion writer and accessories buyer for www.moonriverpearls.com. She
welcomes your questions. Reach her at adrescher@moonriverpearls.com.
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