Origin of Name :-
Scallop Pearls or Lion's Paw Pearls, are extremely
rare non-nacreous pearls, produced by a bivalve mollusk, commonly known
as the Scallop, Lion's Paw or in Spanish "Mano de Leon" (hand of the
lion), belonging to the class Pelecypoda and family Pectinidae. The
family name Pectinidae has been derived
from the ancient Latin name, Pecten, meaning "comb," given for scallops
by Pliny the Elder, the Roman author, naturalist and philosopher,
because of their round and ridged outline with radiating ribs that
resembled a type of comb used during the Roman empire. The name
"scallop" is derived from the Old French "escalope," which means shell. Two of the pearl
producing Scallop species are mainly found on the Pacific coast off Baja
California or in the Atlantic coast off northeast America, from
Newfoundland to North Carolina, and these pearls are sometimes referred to by their
ocean of origin, as Pacific scallop pearls and Atlantic scallop pearls
respectively.
The world's most
prolific pearl producers, oysters and mussels belong to the class
Bivalvia, and produce the much sought after nacreous pearls
The world's most prolific pearl producers, the
oysters and mussels that produce saltwater pearls and freshwater pearls
respectively, also belong to the bivalve mollusks (class : Bivalvia),
and these pearls are known as nacreous pearls, as the biogenic material
of which they are composed, is known as "nacre," consisting of layers of
microscopic platelets of aragonite and/or calcite (calcium carbonate),
bound together by a fine network of a complex scleroprotein, called
conchiolin, which imparts spectacular optical effects on the pearls,
such as luster, orient or iridescence and overtone colors.
Saltwater clams and
scallops also belong to the class Bivalvia, but produce extremely rare
non-nacreous pearls
Saltwater
clams and scallops, that also belong to the Bivalvia, rarely produce
pearls, but these pearls are non-nacreous, as the pearl forming
substance is mainly composed of calcite that do not form microscopic
platelets, but long microcrystalline needles, that do not scatter light,
and hence do not impart the characteristic luster, orient and overtones
of nacreous pearls. Among the saltwater clams that produce non-nacreous
pearls are the Quahog clam, Mercenaria mercenaria, found along the
Atlantic coastline of north America, that produces the rare Quahog
pearl, and the giant clam, Tridacna gigas, found on the coral reefs, off
the coast of the Island of Palawan, in the Philippines, and on the Great
Barrier Reef, off the coast of Queensland in northeast Australia, that
produces extremely rare and sometimes massive calcareous concretions, such as the
"Pearl of Allah" and the "Palawan Princess," reputed to be among the
world's largest pearls. Among the Scallops, there are four species that
are known to produce pearls. These species are the Atlantic Lion's Paw (Nodipecten
nodosus), the Pacific Lion's Paw (Nodipecten subnodosus), the Atlantic
Sea Scallop (Placopecten magellanicus), and the Atlantic bay scallop (Argopecten
irradians).
The bailer volute,
the queen conch and horse conch are sea-snails that belong to the class
Gastropoda of the Phylum Mollusca, and produce extremely rare
non-nacreous pearls
In the Gastropod mollusks (class : Gastropoda),
pearls produced by sea-snails, such as Melo melo sea-snail (bailer
volute) that produces the extremely rare melo-melo pearl, Strombus gigas
sea snail (queen conch) that produces the rare conch pearls, and
Pleuroploca gigantea (horse conch) that also produces rare horse-conch pearls,
are all non-nacreous pearls. Usually pearls produced by sea-snails are
non-nacreous, but here too there can be exceptions, such as the Abalone
sea-snail that produces nacreous pearls, whose color, brilliance and
luster is unsurpassed by all other natural pearls.
Important conclusions
that can be derived from the above information
Thus from the above information we can arrive at the
following general conclusions :-
1) That nacreous pearls are generally produced by
bivalve mollusks, such as the seawater oysters and freshwater mussels,
except abalone pearls that are produced by the univalve mollusk
(gastropod mollusk), the abalone sea-snail.
2) That non-nacreous pearls are generally produced by
univalve mollusks (gastropod mollusks), such as melo-melo pearls, and
conch pearls, except quahog pearls, giant clam pearls and scallop pearls
that are produced by bivalve mollusks.
3) The occurrence of all natural pearls are generally
rare, but the occurrence of nacreous pearls is relatively greater than
the occurrence of non-nacreous pearls. The occurrence of most
non-nacreous pearls is extremely rare, such as the melo-melo pearl, the
quahog pearls and the scallop pearls.
4) Nacreous pearls both saltwater and freshwater have
been successfully cultured, beginning with the Akoya pearl cultured by
Mikimoto in Japan 1916. Non-nacreous pearls have not been successfully
cultured up to now. Thus most of the non-nacreous pearls that appear in
the pearl markets from time to time are all, without any doubt, natural
pearls. However, recently a successful breakthrough has been achieved in
the culturing of conch pearls from the Atlantic and Caribbean queen
conch sea-snail, by research scientists at the Florida Atlantic
University's Harbor Branch Oceanographic Institute. The research
scientists Dr. Héctor Acosta-Salmón and Dr. Megan Davis who are the
co-inventors of the novel and proprietary seeding techniques to produce
beaded and non-beaded cultured pearls from the queen conch, have
successfully produced more than 200 high-quality cultured conch pearls
applying this technique. The pearls have been handed over to the GIA for
extensive testing at its state-of-the-art laboratories, and initial
tests have revealed that several of the pearls tested were indeed
top-quality gems.
The rarity of
non-nacreous pearls
Non-nacreous pearls are generally much rarer than
nacreous pearls. the following is an attempt to quantify their rarity
based on available information.
Probability of
occurrence of gem-quality conch pearls is 1 in a million
For conch pearls, produced by the Atlantic and
Caribbean queen-conch, Strombus gigas, the frequency of occurrence is
about 1 in 10,000 sea-snails, out of which only about 1 in 100 is gem-quality.
Thus gem quality conch pearls are indeed very rare, with a probability
of occurrence of 1/10,000 x 1/100 = 1/1,000,000 i.e. 1 in 1 million.
Probability of
occurrence of gem-quality quahog pearls is 1 in 2 million
For Quahog pearls, produced by the Quahog clams, the
frequency of occurrence of a purple pearl was given as 1 in 100,000, out
of which only 1 in 20 was said to be of gem-quality. This gives a
probability of occurrence of 1/100,000 x 1/20 = 1/2,000,000 i.e. 1 in 2
million. This is an extremely rare occurrence, and purple quahog pearls
are considered to be the rarest of all natural pearls.
Melo-melo
pearls from southeast Asia were extremely rare that they were not known in the west until
recently
Melo-melo pearls like Quahog pearls are also one of
the rarest natural pearls in the world, but unfortunately statistics of
their occurrence are not available. Hence the computation of their
probability of occurrence is difficult. However, the experience of
sea-snail fisherman, divers, people involved in the cleaning and
processing of its meat for consumption, has shown that during their
lifetime they had seen just one or two pearls, or sometimes never seen
any pearls at all. Melo-melo pearls were so so rare, that they were not
known at all in the west, until as recently as the 1990s. Even the "Book
of the Pearl" by George F. Kunz, the most comprehensive compendium on pearls of the world,
published in 1908, had no reference to the rare melo-melo pearls of
Southeast Asia.
The extreme rarity
of Giant Clam pearls
Giant clam pearls became internationally renowned
after the discovery of the 6.1 kg "Pearl of Allah" the largest pearl ever
discovered from a mollusk, and the largest non-nacreous pearl ever
discovered, in 1934, from the coral reefs off the Island of Palawan, in
the Philippines. Since then the discovery of not more than 10 such
massive calcareous concretions from the giant clam, Tridacna gigas has
been reported, during a period of 76 years. This gives a clear
indication of their extreme rarity. Such massive non-nacreous pearls,
usually referred to as calcareous concretions, have a great collector's
value due to their extreme rarity. The most recent of such finds was the
2.27 kg "Palawan Princess" the second largest non-nacreous pearl, ever
discovered, that came up for sale, at a Bonham's auction, held on
December 6, 2009.
The probability of
occurrence of gem-quality scallop pearls is around 1 in 50,000
Wild scallops are mainly harvested by scallop
fisherman for their meat, and any pearls collected are by products of
this scallop fishing industry. The wild scallops harvested are cleaned
on board the fishing vessels, and the viscera and shells thrown
overboard. The shucking of scallops is done manually, and the process is
very fast, that any pearls on the shell or within the mantle, may not be
seen before the shells and viscera are thrown overboard. It is only the
adductor muscle of the scallop that is used as meat, and the other parts
of the mollusk are discarded. It has been estimated that only around 1
in 10,000 scallops produce pearls. Out of this around 1 in 5 pearls are
gem-quality. Thus the probability of occurrence of gem-quality scallop
pearls is 1/10,000 x 1/5 = 1/50,000 i.e. 1 in 50,000. This is quite high
when compared to the occurrence of conch pearls and quahog pearls, which
is 1 in 1 million and 1 in 2 million respectively. Thus, contrary to the
common belief, gem-quality scallop pearls are not so scarce as queen conch
pearls and quahog pearls. This is due to the occurrence of a higher
percentage of gem-quality pearls in a given quantity of pearls
harvested.
According to Craig Fancy of Fancy Jewelers, based in
Annapolis Royal, Nova Scotia, Canada, who had been designing and
manufacturing jewelry using scallop pearls, since around 1989, a 35-mm
film canister holds about 200 pieces of scallop pearls of about 3-5 mm
in diameter. Of these, he says there may be about 10 pearls, that have a
near-perfect symmetry, such as spherical and near-spherical, and having
the best color. i.e. about 1 in 20 belong to this category. Of the
remaining he says, there will be about 30 pearls that have good color
and some symmetry, such as buttons, drops and ovals. which can be ground
or polished to make setting easier. The rest are too small, misshapen,
or an undesirable brown color. Thus, out of the 200 scallop pearls, 40
pearls are of gem-quality, suitable for setting in jewelry. The
frequency of occurrence of gem-quality scallop pearls in harvested
scallop pearls, is therefore 40 in 200, which works out to 1 in 5. This
is the frequency that has been used in the above calculation. Due to the
low frequency of occurrence of scallop pearls in the wild, around 1 in
10,000, it is said that a typical scallop fisherman might discover only
a handful of these rare beauties throughout his entire career.
Characteristics of
Scallop pearls
Characteristics of scallop pearls depend on the
species of scallop from which the pearls were harvested, which
necessarily means the source or the geographic range where the species
is found predominantly. Thus, we have two main types of scallop pearls
:- the Pacific scallop pearls and the Atlantic scallop pearls.
The Pacific Scallop
pearls
Originate from the
species Nodipecten subnodosus
Pacific scallop pearls originate from the scallop
species found in the Pacific, known as Nodipecten subnodosus (Pacific
Lion's Paw), mainly in the coastal waters off Central America, such as
the waters off the coast of Baja California. It is also found in the
inland Sea of Cortez in Mexico.
The size of the
scallop pearls
These scallop pearls vary in size, from the size of
seed pearls to a maximum of around 40 carats. In terms of dimensions,
this may mean from less than 2 mm to over 10 mm in size. Rarely pearls
are multiple, with several pearls combined together.
Shape of the
scallop pearls
The finding of Craig Fancy for Atlantic scallop
pearls, that out of around 200 pearls, 40 are gem-quality, with the
desired shape, symmetry and color, also holds good for Pacific scallop
pearls. Thus only one out of five harvested scallop pearls have some
form of symmetry in their shape. The rest are either too small, or
irregular, baroque pearls or have an undesirable brown color. One out of
five or 20% of harvested scallop pearls having desirable shapes, is
quite high, which led to some accounts of scallop pearls characterizing
them as natural pearls that are mostly symmetrical in shape, which is
strictly speaking not true. The symmetrical shapes that one comes across
in these pearls are round, near-round, button, drops and ovals.
Color of the
pearls
Pacific scallop pearls have a wide range of colors,
that vary from the lighter tones, such as white, cream, yellow, pink and
mauve (pale purple) to the darker tones such as orange, brown,
deep-purple, plum (reddish-purple), maroon (dark brownish-red) and
brownish-purple. Most scallop pearls have a mosaic or mottling of light
and dark colors, which is believed to be an optical phenomenon. The
lighter color is invariably white, cream or yellow and the darker
colors, brown, brownish-purple, plum and maroon. Scallop pearls with a
single color are very rare.
Appearance of the
pearls
Being non-nacreous, scallop pearls lack the
brilliance (luster) and orient of nacreous pearls. But, as if to compensate for
this the calcite microcrystalline bundles of fibers, arranged parallely
as seen in SEM images, impart a unique 3-dimensional effect or sheen on
the pearl, when viewed in light, also known as a flash effect, similar
to the flame structure of conch and melo-melo pearls. According to the
CIBJO's description of scallop pearls, the surface appearance of scallop
pearls is comprised of a patchwork of cells, with each cell being
formed from three sub-cells. The orientation of these sub-cells and the
low magnification fibrous appearance of structures within them, give the
scallop pearl a peculiar surface sheen.
The Atlantic scallop
pearls
Atlantic scallop pearls can
originate from three different species, but the most important one is Placopecten magellanicus around which a successful commercial fishery
exists
Atlantic scallop pearls can originate from three
different species of scallops found in the northeastern North American
region, the natural geographic range of these scallops. These species
are the North Atlantic deep-sea scallop, Placopecten magellanicus; the
Atlantic bay scallop, Argopecten irradians, and the Atlantic Lion's Paw,
Nodipecten nodosus. The scallops occur along the continental shelf of
North America from Newfoundland and Labrador to Cape Hatteras in North
Carolina. North of Cape Cod in the State of Massachusetts, scattered
concentrations of scallops occur in shallow water, just below the low
tide mark. Further south concentrations are restricted to deeper and
cooler off shore waters. This is because Sea Scallops cannot tolerate
water temperatures above 20 to 22°C. Dense and
extensive scallop beds that can support commercial fishing exist from
Port au Bay, Newfoundland to the Virginia Capes, at depths of between 40
to 100 meters. The species found at these depths is Placopecten
magellanicus, the North Atlantic deep-sea scallop. Digby in Nova Scotia,
"the Scallop Capital of the World" is the center of a commercially
important deep sea scallop fishery as well as inshore fishery,
harvesting the smaller bay scallop (Argopecten irradians) in the Bay of
Fundy off Digby.
Size of
Atlantic scallop pearls
The Atlantic scallop pearls are a by product of a
thriving scallop fishery taking place at several places along the
geographic range of the deep sea scallop, including the important
fishery out of Digby, Nova Scotia. Pearls produced by the deep-sea
scallop Placopecten magellanicus are usually irregular (baroque) and
small, with a size of around 1-2 mm (seed pearls). However, older
animals produce larger pearls, with an average size of 3-5 mm and
sometimes can reach a size of 5-6 mm. Pearls lager than this are very
rare, but Craig Fancy had owned some exceptional specimens, such as two
button-shaped scallop pearls with dimensions of 10 x 9 mm and 12.2 x 8.5
mm; a large baroque pearl, with dimensions of 20 x 9 x 8 mm; and four
large round pearls with dimensions of 8-11 mm.
Shape of
Atlantic scallop pearls
Most of the Atlantic scallop pearls are small and
baroque in shape, less than 2 mm in size and falling under seed pearls.
Craig Fancy, the pioneer jeweler from Nova Scotia, who first began
setting Atlantic scallop pearls on pieces of jewelry, in the 1990s,
estimated that out of around 200 scallop pearls only around 40 were of
gem-quality, with the desired symmetrical shape, and color. This works
out to 1 in 5 or 20% of harvested pearls. The symmetrical shapes that
were found were round, near-round, button, drop and oval.
Color of Atlantic
scallop pearls
Gem-quality Atlantic scallop pearls were white,
off-white, or pale-tan in color. Non gem-quality scallop pearls were
small, misshapen (baroque) and have an undesirable brown color.
Appearance of the
pearls
The pearls are non-nacreous and do not have the
luster and orient of nacreous pearls. However, the pearls have a silvery
sheen, that complement the white and pale-tan colors of the pearls, an
optical effect caused by the parallel calcite fibers on the surface, a
3-D effect, also known as a flash effect. This is similar to the
chatoyancy caused in gemstones such as beryls, sapphires, quartz etc
that produces a catseye effect or star effect, an optical effect caused
by rutile fibers.
How Scallop
pearls became popular in recent times ?
Scallop pearls had no
market value and their existence was overlooked for a very long time, in
a world dominated by cultured pearls
The existence of scallop pearls had been known by
scallop fisherman of the Atlantic coast of northeast America for a long
time, who had found them casually while shucking harvested scallops for
their meat, on board their fishing vessels. However, as pointed out
earlier the shucking process is so quick, lasting just a few seconds, in
order to preserve the volume and quality of the meat, that any pearls on
the shell or within the mantle cavity, may not be discovered, before the
shells and viscera are thrown overboard. Perhaps, one reason for the
lack of concern, for the possible existence of a pearl inside a scallop,
was because the scallop pearl was largely unknown to the outside world,
and had no market value at all.
Scallop pearls became
popular only after the resurgence in demand for natural pearls beginning
from the 1990s
This was in complete contrast to conch pearls, also a
by product of the queen conch fishery in the Caribbean, that became very
popular in the late-Victorian and Edwardian periods, but whose
popularity died down soon after the end of world war I, when the
successful culturing of Akoya pearls by the Japanese, flooded the pearl
markets of the world, with a range of cultured pearls, in a variety of
colors, shapes and sizes, and at affordable prices. The success of the
Japanese, dealt a death blow, to the natural pearl fishing industry
across the world. Unlike conch pearls, scallop pearls had never been
known to the world before, and when the scallop fishing industry
developed, even though their existence came to light, it did not create
any impact as the natural pearl industry was virtually dead, in a world
dominated by Mikimoto's cultured pearls. The cultured pearl industry had
dominated the pearl markets for over eight decades. However, beginning
in the 1990s, there had been a resurgence in the demand for natural
pearls in the Middle East , Europe and America, which was clearly
reflected in enhanced prices realized for pieces of jewelry
incorporating old natural Oriental, Venezuelan, and black Tahitian
pearls, at auctions conducted by renowned auction houses, such as
Christie's and Sotheby's. See table below. The increase in demand for
old natural pearls was followed by an increase in demand for other
contemporary natural pearls, such as conch pearls, abalone pearls,
freshwater natural pearls from America, quahog pearls, melo-melo pearls
and finally the scallop pearls.
Table of some
famous natural pearls/pearl jewelry sold at public auctions conducted by
international auction houses, giving the date of auction and the prices
realized, during the period 1970 to 2009. The table shows a resurgence
in demand after around 1986.
| S/N |
Name of pearl/pearl jewelry |
Probable period of origin |
weight |
date of auction |
Price realized |
| 1 |
La Peregrina |
1513 |
203.84 grains |
1969 |
USD 37,000 |
| 2 |
Mancini pearls |
1500-1600 |
400 grains |
Oct.1979 |
USD 253,000 |
| 3 |
Mona Bismarck 2-strand pearl necklace |
1920-1930 |
Double-strand of 70 pearls |
May 1986 |
USD 410,000 |
| 4 |
Duchess of Windsor pearl necklace |
1910-1936 |
Single-strand of 28 natural pearls. Total
weight 1266.33 grains |
April 1987 Dec 2007 |
USD 733,333 3,625,000 |
| 5 |
Empress Eugenie tiara |
1853 |
212 pearls, 2,520 grains |
Nov 1992 |
USD 650,000 |
| 6 |
Nina Dyer black pearl necklace |
1950s |
151 natural black pearls |
Nov 1997 |
USD 913,320 |
| 7 |
Barbara Hutton pearls |
1600-1666 |
44 natural pearls, total weight of 1,816.68
grains |
May 1992 Nov 1999 |
USD 580,000 USD 1,470,000 |
| 8 |
Unidentified natural pearl necklace by
Cartier |
Historical provenance not revealed |
Double-strand necklace with 88 natural pearls |
Nov 2004 |
USD 3,100,000 |
| 9 |
La Regente |
1811 |
302.68 grains |
Nov 2005 |
USD 2,483,968 |
| 10 |
Gulf pearl parure designed by Harry Winston |
1932-1978 |
|
Nov 2006 |
USD 4,100,000 |
| 11 |
Baroda pearl necklace |
1856-1870 |
Double-strand with 68 natural pearls from the
original 7-strand necklace |
April 2007 |
USD 7,096,000 |
| 12 |
Umm Kulthum pearl necklace |
1880 |
nine-stranded necklace with 1,888 pearls |
April 2008 |
USD 1,390,000 |
| 13 |
Pearl necklace from an unidentified notable
collection |
Historical provenance not revealed |
Single-strand necklace with 41 natural pearls |
Nov 2008 |
USD 1,321,110 |
| 14 |
Unidentified pearl and diamond festoon
necklace |
Historical provenance not revealed |
Nine-strand pearl and diamond festoon
necklace. Length 645mm to 1060mm |
Nov 2008 |
USD 946,610 |
| 15 |
Pearl Carpet of Baroda |
1860 |
1.5-2.0 million natural seed pearls |
March 2009 |
USD 5,500,000 |
Pacific scallop
pearls received international attention after their exhibition and sale
at the year 2000 Tucson show
In fact it was only after the Tucson show of year
2000, that Pacific scallop pearls received international attention,
after their exhibition and sale at the show, by Wes Rankin, the natural
pearl dealer, of Pacific Coast Pearls, Petaluma, California. The scallop
pearls that were offered at the Tuscon show, were the Pacific scallop
pearls, that occurred in a wide range of colors, with their
characteristic mosaic or mottling of light and dark colors. Since then
Wes Rankin had sold an average of 100 Pacific scallop pearls every year,
which he purchased from divers. Presently, the demand for Pacific
scallop pearls has exceeded all expectations, and the annual supply of
these pearls is hardly enough to meet the rapidly increasing demand. The
present price range for these pearls is between $100 to $2,000 per carat
depending on the quality of the pearl. One of the most beautiful scallop
pearls, which Wes Rankin had ever seen, an 18-carat oval pearl, with a
nutmeg-orange color, was sold by him to an Asian collector, at a price
of $36,000 in the year 2004, a record price for a scallop pearl, that
gives a price per carat value of $2,000.
Atlantic scallop
pearls also became popular around the same period after Craig Fancy of
Nova Scotia set them in attractive and affordable pieces of jewelry made
out of 14K gold
The recent upsurge in the popularity of Atlantic
scallop pearls, is also attributed to one single jeweler, Craig Fancy of
Fancy Jewelers, based in Annapolis Royal, Nova Scotia, Canada, who had
been turning out pieces of jewelry using Atlantic scallop pearls, since
around 1989. During that year a scallop fisherman brought some scallop
pearls, asking him to set them in a pendant for his wife, which he did.
During the next 6 to 8 years more requests came in, and he set scallop
pearls of different sizes and shapes in custom-made designs, to suit the
taste of his customers. He then began designing pieces of jewelry, that
were not only attractive but affordable, in the local as well as the
tourist markets. He developed several designs for pendants,
earrings and rings in 14K gold, that suit the delicate nature of
the pearls very well. These pieces of jewelry are sold at his family
jewelry stores in Annapolis Royal and Digby. The supply of Atlantic
scallop pearls is still small and unreliable, and the chances of the
Digby scallop pearls turning into a major new industry in Canada are
still remote.
Classification of
Atlantic Sea Scallop
Kingdom
: Animalia
Phylum
: Mollusca
Class
: Bivalvia
Order
; Ostreoida
Family
: Pectenidae
Genus
: Placopecten
species
: magellanicus
Common name :
Atlantic sea scallop
The worldwide scallop
fishery is a billion-dollar industry
The largest wild scallop fishery in the world is
based on the scallop species Atlantic sea scallop, Placopecten
magellanicus, found off northeastern United States and eastern Canada.
The U.S. fishery, the largest wild scallop fishery in the world, based
on the Atlantic sea scallop had an output of 53.5 million pounds
of sea scallop meat in 2008, worth $370 million. The industry was mainly
centered around Massachusetts and New Jersey. Japan has a scallop
fishery based on both wild and cultured scallops, and China, a fishery
based only on cultured Atlantic bay scallop, Argopecten irradians. In
Europe, Russia was the main leader in the industry. The entire worldwide
scallop fishery is worth billions of dollars. The scallop fishery seem
to be based around scallop species adapted to cooler temperate waters. However, scallops
are a cosmopolitan family, with around 350 species, found around the
world, in all of the world's oceans.
Uses of Scallops
1) As a source of food :-
Scallop meat is valued as a
food in many Western as well as Eastern countries (China and Japan). In
some countries such as the United States and Canada, only the well
developed adductor muscle is used as meat, while in other countries
apart from the adductor muscle, other parts of the scallop are also
used. Scallop fishery is an industry found in many countries across the
world with an annual value running into billions of dollars.
Fortunately, the industry has been well managed in many countries, with
a minimum of impact on wild populations.
2) As a source of non-nacreous pearls :- An important
by product of the worldwide scallop fishery is the extremely rare
scallop pearl, a non-nacreous pearl, with a unique 3-dimensional effect
that produces a metallic sheen. Since the resurgence in demand for
natural pearls, beginning from the 1990s, scallop pearls have come to
the forefront as the latest natural pearl, commanding premium prices.
3) Scallop shells valued as a collector's item :- The
decorative, brightly- colored fan-shaped shells of some scallops are
highly valued by shell collectors.
4) Decorative and ornamental value :-
Brightly-colored scallop shells has a decorative and ornamental value,
used in household decoration or turned into pieces of jewelry.
5) As a decorative motif :- The regular and pleasing
geometric shape of the scallop shell, has inspired artists as a
decorative motif, and has been used as a motif on the edge of draperies,
clothing and also in jewelry.
5) Symbolic value - Brightly-colored and
decorative scallop shells, had a symbolic value since very ancient
times. Greek temples and Roman vases, were adorned with scallop shell
motifs. The Triton Fountain in Rome of mediaeval origin, made of marble
and designed by Bernini in 1642, depicts Triton, the son of sea god
Poseidon, perched on a large, open, scallop shell, supported by two
dolphins.
In the middle ages Scallop shells were worn as
a badge by pilgrims to the shrine of St. James the Apostle in
Campostello, Spain. The Apostle St. James association with the scallop
can be traced to the legend that he once rescued a knight covered in
scallops, or that when St. James remains were being transported to Spain
from Jerusalem, the horse of a knight fell into the water, and emerged
covered in the shells. The French name for a dish containing scallops,
"Coquille St. Jacques" meaning "shell of St. James," appears to be
associated with this legend.
The scallop was considered a symbol of fertility by
ancient Romans, who associated it with Venus, the Roman goddess of love
and fertility. Paintings of the goddess was always associated with a
scallop shell.
The scallop shell symbol entered the coat-of-arms of
many families, as a badge of those who had been on pilgrimage to
Compostela, and later a symbol of pilgrimage in general. Sir Winston
Churchill's family coat-of-arms included a scallop.
The Atlantic bay scallop was adopted as New York
State's official "State Shell" in 1988.
The scallop shell is also the inspiration for not
only the symbol, but also the name, of one of the most successful energy
and petrochemical companies in the world, based in Netherlands, The
Royal Dutch Shell Plc. which has become an international household word.
Scallop "eyes" along the edges of the mantle
The structure of
scallops
Scallops like true oysters are marine bivalve
mollusks, with a soft body, protected by two hard shells or valves. The
shape of the shells are highly regular and ridged, the lower valve
usually larger than the upper, with flared ears at the hinge. Ridges
radiate out from the hinge along each valve in the shape of a fan. The
edges of the shells are sharp and undulating, because of the ridges. The
valves are opened and closed by a single large adductor muscle, which is
more developed than that of oysters, because scallops are active
swimmers. In fact scallops are the only migratory bivalves that can move
from one place to another. Along the edges of the mantle are several
eyes, with a lens and retina, that are more complex compared to other
bivalves, yet primitive, as they cannot see shapes, but can detect light
and motion.
Atlantic Bay Scallop
© New York State
Department of Environmental Conservation
Atlantic Scallop Pearl- Placopecten magellanicus
© NOAA
Placopecten magellanicus, the Atlantic sea scallop
has a broad shell, which is almost circular and flattened at the
hinge, and attaining a height of 15-20 cm. The shells are without ribs,
having only radial striae. The right valve is smoother than the left.
The ears are unequal and the valves have a slight convexity. The color
of the shell is yellowish-grey to purplish-grey, or dirty-white. The
inner surface of the shell is flaky-white.
Feeding and
Locomotion
Scallops like other bivalve mollusks are filter
feeders, feeding on suspended food particles in the water, such as
phytoplankton and other organic detritus, that are brought in by the
incurrent siphon, filtered and trapped in mucus as the water passes over
the gills. The action of the cilia on the gills, direct the food
particles towards the mouth, which are then ingested.
Most scallops are free living, but some species
attach themselves to the substrate after becoming adults, by byssal
threads. Some species can burrow into the substrate by extending their
foot. Free living young scallops are mobile, using jet propulsion to
move, by opening and closing their shells quickly, and squirting water
out by the ears of the shells in spurts. However, as the animals grow
older and larger, they gradually lose this ability. The movement of
scallops help them to escape from predators such as certain species of
cod, wolffish, eel pout, flounder, crabs and lobsters.
Reproduction
Among the scallops some species are dioecious, male
and female sexes being separate, while others are monoecious, both sexes
being found in the same individual. Monoeciuos scallops, can be
simultaneous hermaphrodites where male and female sex organs mature at
the same time, or protoandrous hermaphrodites, being males when young
and becoming females when old. Scallops attain reproductive maturity at
the age of 2 years, but take part in active reproduction only around 4
years of age. When sex organs are mature, millions of spermatozoa
and ova are released freely into the surrounding water where
fertilization takes place. Fertilized ova sink to the bottom of the bed,
where after several weeks they hatch to form larvae, which drift about
in the water, and later settle at the bottom, attaching by byssal
threads. Some scallops are short lived eg. Atlantic bay scallop, while
others can live up to 20 years or more. Annuli on the shells can be used
to estimate the age of scallops. They grow rapidly during the first half
of their life span. It has been estimated that between the ages of 3 and
5 years, sea scallops grow up to 50 to 80% of their shell height (10-16
cm) and increase their meat weight four times. They can reach a maximum
height of around 20 cm, but instances have been reported where the
height of the shell reached 22-23 cm.
Harvesting and
processing of
scallops
Specially rigged boats called "draggers" are used in
harvesting scallops at depths of 40 to 100 meters. Drags equipped with
large wire-mesh bags, are towed along the bottom of the ocean by these
draggers. The drags are lifted on to the boats and the wire-mesh bags
emptied. Empty shells and other debris are often found together with the
scallops. Opening of scallops are done manually using a shucking knife,
as successful mechanical shucking methods have not been developed up to
now. The method is tedious, as every scallop has to be opened
individually. The shucking knife is run around between the shells,
cutting through the adductor muscle and flipping off the upper shell.
The viscera is then lifted and pulled away, by running the knife under
its edge, leaving the adductor muscle still attached to the lower shell.
The adductor muscle known as the "meat" is then cut off and separated
from the lower shell and placed in pails for processing. The scallop
meat is treated with sodium tripolyphosphate (STP), before packing and
freezing, a process known as wet-packing. STP causes scallop meat to
absorb moisture before freezing, giving the fisherman a better price per
unit of weight. When scallops are packed and frozen without adding any
additives, the process is known as "dry packing."
You are welcome to discuss this
post/related topics with Dr Shihaan and other experts from around the
world in our
FORUMS (forums.internetstones.com)
Related :-
1)
Melo Melo Pearls
2)
Queen Mary Conch Pearl Brooch
3)
Pearl of Allah / Pearl of Lao Tzu
4)
Golash Quahog Pearl Brooch
5)
Big Pink Pearl
External Links :-
1)
Scallop Pearl Jewelry - created from World Famous Digby Scallops -Willow Wight. www.scalloppearl.ca
References :-
1) Scallop Pearls From Digby, Nova Scotia - Willow
Wight. www.scalloppearl.ca
2) Gem Profile 23 : Scallop Pearl.
www.airesjewelers.com
3) Scallop Pearls - www.pearl-guide.com
4) Scallop Pearls - www.allnaturalpearls.com
5) Scallop - From Wikipedia, the free encyclopedia
6) Atlantic Sea Scallop - FishWatch - U.S.
Seafood Facts. National Marine Fisheries Service. www.nmfs.noaa.gov
