Origin of Name :-'
Melo Melo pearls
originate from a gastropod mollusk known as the melo-melo sea-snail or
bailer volute
Melo Melo pearls are extremely rare non-nacreous
pearls produced by the gastropod mollusk commonly known as the melo-melo
sea snail, zebra sea-snail or bailer volute, belonging to the family
Volutidae, and given the scientific name Melo melo. Thus melo melo
pearls derive their name from the scientific name of the sea-snail that
produces them. The sea-snail earned
its name "bailer volute" because the large shell of the snail was often
used to bail water out of boats. It should be noted that the Melo melo
snail belongs to the Phylum Mollusca, under which there are three main
classes, the Bivalvia (oysters, mussels, clams, scallops etc.), the
Gastropoda ( sea-snails, land snails, slugs, periwinkles, whelks and
abalone etc.), and the Cephalopoda (octopus, squids, cuttle fish and
nautilus ). Thus sea-snails such as Melo melo (bailer volute), Strombus
gigas (queen conch) and Pleuroploca gigantea (horse conch), that are
known to produce non-nacreous pearls, belong to the gastropod mollusks.
In this context the following statement made in some popular pearl
websites, is both confusing and totally misleading :-"The melo
melo "pearl" does not come from an oyster or mollusk, but comes instead
from the melo melo marine snail" Undoubtedly, the melo melo pearl
does not originate in an oyster, which is a bivalve mollusk, but in the
same breath the statement declares, that the pearl does not arise in a
mollusk either. The statement continues that the pearl originates in the
melo melo marine snail. The statement is contradictory, and whoever who
made it, apparently doesn't seem to know, that melo melo marine snails
are also mollusks falling under the class gastropoda.
A Shell of Melo melo sea-snail with a group of
melo-melo pearls
Photo Above Creative Commons
Melo Melo pearls are
non-nacreous pearls
What distinguishes a
"true pearl" from non-nacreous pearls ?
Being produced by a gastropod mollusk
like conch pearls, melo melo pearls do not qualify to be classified
under "true pearls," a term reserved only for nacreous pearls produced
by bivalve mollusks, such as saltwater oysters and freshwater mussels.
Even pearls produced by certain clams such as the quahog clam, which are
also bivalve mollusks are not considered to be "true pearls" as they are
non-nacreous. Thus, what actually distinguishes a true pearl from a
non-nacreous pearl, previously known as calcareous concretions, is the
presence or absence of "nacre," an organic/inorganic complex material,
that imparts the unique luster and iridescence, characteristic of these
pearls.
Intense-orange melo-melo pearl
The composition of
nacre and what causes the characteristic luster and iridescence
The organic component of nacre is the scleroprotein conchiolin,
while the inorganic component is crystalline calcium carbonate, mainly
aragonite together with some calcite. Aragonite is found mainly as tiny
hexagonal platelets with a width of 10-20 µm
and thickness of 0.5 µm. These platelets are
arranged in parallel lamina, separated by conchiolin. The thickness of
the aragonite platelets, is comparable to the wavelength of visible
light, causing the scattering of different colors in white light,
producing the characteristic iridescent effect.
The composition of
non-nacreous pearls, and reasons for absence of iridescence and presence
of chatoyancy
In non-nacreous pearls, the pearl
forming substance is chemically related to nacre, but the crystalline
form of calcium carbonate that forms the inorganic component is mainly
calcite and not aragonite. Moreover, the calcite microcrystals do not
form tiny hexagonal platelets but long needles that do not scatter
light. Hence, the absence of iridescence in non-nacreous pearls. The
microcrystalline calcite needles are associated together to form
bundles of fibers, whose arrangement and alignment, causes a type of "chatoyancy"
when light falls on the fibers, known as a "flame structure." In melo
melo pearls, particularly the most sought-after intense orange-hued
ones, the effect of the shimmering flame structure, combined with the
porcellaneous luster is spectacular, even surpassing the beauty of some
nacreous pearls, that has triggered a debate whether the continued
classification of these rare beauties of nature, as non-nacreous pearls
is justified.
Yellowish-orange melo-melo pearl
The natural habitat
of the Melo melo sea snail
The geographic range
of the Melo melo sea-snail - the Indo-Pacific region
The natural habitat of the Melo melo sea-snail are
the seas of the Southeast Asian region, the South China Sea, the Gulf of
Thailand, the Andaman Sea, and the Bay of Bengal closer to Burma. The
waters off Vietnam in the South China Sea, is a well known habitat of
the sea-snail, a primary source of the rare melo-melo pearls produced by
these sea snails. Other habitats include the waters off Thailand in the Gulf of Thailand; Burma in the Bay of
Bengal; the Andaman Islands in the Andaman Sea; Cambodia, Malaysia,
Singapore, Indonesian archipelago and Philippines
in the South China Sea. They are also found off
the coast of Northern Australia, in the South China Sea. This region
where the sea-snail occurs is known as the Indo-Pacific region, and the
South China Sea, is the sea that connects the Indian and
Pacific Oceans.
Melo melo sea snail at Beting
Bronok, Singapore
©Wild singapore
.COM
The main areas in
Vietnam where the sea-snails are found abundantly
In Vietnam, the Melo-melo snail is found in the
waters of the picturesque Halong Bay - the "Bay of Dragons," along the
northern coast of Vietnam. Within the bay itself an area that is rich in melo sea-snails are the sand banks around the Bach Long Vi islands, a
small island located halfway between Haipong and Hainan Island. However,
most of the sea-snails that are harvested in Vietnam by trawlers
originating from the fishing harbors of Thanh Hoa and Quang Ngai
come from the waters surrounding the distant islands of Spartly and
Paracel in the South China Sea, two groups of islands whose ownership is
disputed between Vietnam and China. The sea-snails are found in sandy
and rocky areas at depths of 20-30 meters. The peak fishing period for
melo melo snails is around April. The snails that are harvested are
transported to the northern Cat Ba Islands, the main trading center for
sea-snails harvested from all over Vietnam, from where dealers who
purchase the snails from the fisherman export them to China. However,
after about 20 years of intensive trawler fishing of the sea-snails,
their harvest has been drastically reduced, and concurrently melo-melo
pearls which were relatively common in the past are becoming scarcer and
scarcer. Vietnam being the primary source of Melo melo pearls, the
pearls are also sometimes referred to as Vietnamese orange pearls.
Young Melo melo sea snail on the shores of Beting
Bronok, Singapore
©Wild singapore
.COM
The areas in Burma
where they are found abundantly
In Burma, Melo melo sea-snails are found along the
Arkan coast, in the southern region of Dawei, the Mergui Archipelago,
and Kawthaung in the Andaman Sea near Thailand. The shells of the snail
are known as "ohn kayu" or "coconut shell" because of their resemblance
to coconuts, and the pearls produced by them are known as "ohn pale"
meaning "coconut pearls." The Melo melo sea-snails are fished at a depth
of 30-50 meters from the muddy sea bottom.
The occurrence of
Melo melo snails in Thailand
In Thailand, Melo melo snails are brought up
occasionally from the bottom of the sea, while fishing for crabs in the
Gulf of Thailand. One reason why the sea-snail is difficult to find is
because it usually inhabits the muddy bottoms of the sea, at depths of
over 20 meters, where it leads
the life of a predator feeding on other small gastropods and sea
creatures. However, according to a Thai scientist Mr. Suraphol
Chunhabundit, marine biologist at the Chulalongkorn University in
Bangkok, the Melo melo sea-snail is nocturnal and during the daytime digs itself into the
sandy bottom leaving only a siphon above the sand. This is precisely the
reason why it is very hard to find and is rarely caught. According to
him the snail feeds on plankton and other small animals at the bottom of
the sea.
The occurrence of
Melo melo snails in Singapore and Malaysia
Two species of volutes have been recorded in the
waters off Singapore and Malaysia - the bailer volute, Melo melo and the noble
volute, Cymbiola nobilis. While the noble volutes are sometimes seen in
the undisturbed northern shores, the bailer volutes are seldom seen at
all, mainly because they inhabit deeper waters. The bailer volute in
Singapore is commonly encountered on the remote offshore reef of Beting
Bronok. The bailer volute is listed as an endangered species in
Singapore, mainly due to habitat loss.
The Melo melo sea-snail
Classification
Phylum : Mollusca
Class : Gastropoda
Subclass : Orthogastropoda
Order : Sorbeoconcha
Sub-order : Hypsogastropoda
Superfamily : Volutoidae
Family : Volutidae
Genus : Melo
Species : melo
Common names : Indian Volute
: Bailer Volute
: Zebra Sea-Snail
Habitat - The Melo
melo sea-snails are found in the sandy or muddy bottoms in the
infra-littoral and circa-littoral sub-zones of the sub-littoral zone
The sub-littoral
zone
The habitat of the Melo melo sea-snail in the
Indo-Pacific region usually extends from the seashore to a depth of
about 70 to 80 meters in the sub-littoral zone. They are predominantly
found in the sandy or muddy bottoms in the infra-littoral and
circa-littoral sub-zones, of the sub-littoral zone.
The sub-littoral zone, begins immediately after the
inter-tidal zone and extends to the edge of the continental shelf, to a
depth of about 200 meters. In this region sunlight reaches the ocean
floor, and makes possible the survival of photosynthetic organisms such
as phytoplankton and sea weeds and grasses. The area is also rich in oxygen, has low
water pressures and relatively stable temperatures and salinity levels.
Thus the sub-littoral zone also known as the Neritic zone is the
location of the majority of sea life, that includes the phytoplankton,
the base of the food pyramid, that supports fish life, and other forms
of sea life such as crustaceans, mollusks etc. The submerged coral reefs
are also found in this region.
The infra-littoral
zone
The sub-littoral zone is divided into infra-littoral
and circa-littoral zones, by marine biologists. The infra-littoral zone
which is an algal dominated zone, extends from the end of the
inter-tidal zone down to the lowest limit, where sea grasses and
photophilic (light-loving) algae can live. In clear seas the lower limit
of this zone can extend up to a depth of 50 meters. Apart from the
unicellular and multicellular floating algal forms (phytoplankton) that
exist in this zone, some of the large photophilic macroalgae that grow
in this region are the brown algae Cystoseira, Dictyopteris and
Sargassum and the green algae Dascycladus. A lot of microhabitats are
created within these algal beds, that support a rich fauna and
flora, that include invertebrates and fishes. Among the invertebrates
are burrowing and sessile organisms such as sponges, and bivalve
mollusks, and burrowing and creeping organisms such as gastropod
mollusks, the bailer volute being one of them. Swimming animals such as fishes and copepods feed, shelter and
lay their eggs in the algal beds.
The circa-littoral
zone
The region beyond the infra-littoral zone is known as
the circa-littoral zone that extends from the lower limit of the
infra-littoral down to the maximum depth where multicellular
photosynthetic forms can exist, which is about 200 meters in depth. At
such depths the light intensity is very low, and therefore vegetation is
sparse consisting of foliose red algae in the shallower areas and
crustose red algae in the deeper areas. Some of the crustose red algae
species found are calcified Lithothamnia and non-calcified Cruoria. The
circa-littoral zone is dominated by animals of the burrowing, sessile and mobile forms. The sessile attached forms include the
tubeworms, bryozoans, sea mats, sponges, corals and sea fans. The
burrowing forms include heart urchins and the gastropod mollusks. Animals that live on the surface
include brittle stars and sea cucumbers, and animals that are partly
embedded in the sediment are sea pens and soft corals. Among the
prominent mobile organisms in this zone are the decapod crustaceans,
echinoderms, mollusks and fishes. The small mobile organisms include the
isopods, amphipods, nemerteans and polychaetes. The sea-snail bailer
volute also exists in this zone in the shallower areas less, than 100
meters, and remains burrowed just below the surface during the daytime.
Feeding and
Reproduction
The bailer volute usually remains buried in the sandy
or muddy bottom of the sea and come out at night to feed. They are
carnivorous, feeding on other predatory gastropods, such as Hemifusus
tuba and Babylonia lutosa and the dog conch, Strombus canarium.
Volutes have a limited location and distribution,
because of their breeding habits. They do not produce free swimming
larvae known as veligers that swim and float over a vast area of the
ocean, such as in oysters and clams, and colonize new areas. The sexes are separate in the
volute
sea-snails, but external differentiation of male and females are
difficult, except perhaps for the difference in sizes. The males have a
single testis where the sperms arise, and are conducted along a coiled
vas deferens to the penis. The females have a single ovary producing
eggs, which are conducted along the oviduct to the pallial oviduct,
where the eggs are fertilized by the sperms introduced by the male. Most
gastropods show a courtship behavior before copulation. The fertilized
eggs are covered with albumen produced by the albumen gland, and then
jelly produced by the capsule gland. The fertilized eggs surrounded by a
gelatinous capsule pass down the remaining part of the oviduct, and are
laid through the genital pore. The eggs remain attached together as a
gelatinous mass, before they hatch into tiny young snails, which look
like adults in all respects. The young snails are on their own until
they develop into adults, provided they are lucky enough to escape from
other predatory gastropods.
The Description of
the Shell
The average length of a Melo melo snail shell is
between 150 mm (15 cm) to 275 mm (27.5 cm), with a reported record size
of 362 mm (36.2 cm). The color of the shell varies from beige to orange,
with a smooth outer surface showing distinguishable growth lines.
Sometimes the shell has dark brown bands while others are without
any distinct markings. The interior of the shell is glossy cream,
becoming light yellow near its margin. The shell has a wide aperture,
nearly as long as the shell itself, a feature that facilitates its use
to bail out water, like a wide-mouthed container.
The large fleshy foot of the snail is brown in color
with white stripes like a zebra. Hence the name zebra sea snail. The
white stripes are also found on the long siphon. These features are
characteristic of the Melo melo volute.
Shell of melo-melo sea snail
Photo Above Creative Commons
The Uses of Bailer
Volutes
1) Source of Food
- Bailer volutes had been put to multiple uses by man since very ancient
times. One of the first uses of bailer volutes for ancient man was as a
source of food, like all other marine mollusks such as oysters, clams,
and other marine gastropods. The Melo melo sea snail is still used as a
delicacy in countries of Southeast Asia, such as Vietnam and China.
2) Container for bailing
water from boats - Another ancient use of the bailer volute,
was the use of its large shell with a wide aperture as a container for
bailing water out of their boats by ancient people like the aborigines
of Australia, from which the shell derives its name.
3) Used as bowls
- The aborigines used bailer shells also as bowls in the kitchen, and
for holding liquids like vegetable oils.
4) Used as a scoop in the
markets - The shells are also used as scoops for salt, sugar
and flower in the local markets, in the regions where they are found.
5) Used as pots for
ornamental plants - Another novel use for the big shells was
as flower pots for ornamental plants.
6) Used as horns in
religious ceremonies and rites - In Myanmar (Burma), melo
shells were sometimes used as horns, like the conch shells, and blown at
religious ceremonies, or while performing religious rites at the
Buddhist temples.
7) Used as ashtrays
- In the coastal villages of Burma, the melo shells are commonly used as
ashtrays for cheroots and cigars.
8) Collectors' value
- Shells of the family volutidae are popular collectors items because of
their decorative nature, and therefore highly valued by shell
collectors. The bailer volute shell is also valued because of its
rarity.
9) Source of non-nacreous
pearls - The Melo melo sea-snails produce one of the rarest,
largest and most spherical natural pearls in the world, with a fiery
orange color. Melo melo pearls were known in Southeast Asia since
ancient times, the pearl being used as a symbol of expression of various
virtues, such as a symbol of perfection in Buddhist thought, as the
pearl requires no enhancement or alteration by man, when it emerges.
10) Melo pearls were used as
marbles - In Burma, where very few people knew about the
value of these pearls, young children played marbles with these pearls
in the days of ignorance.
History of the usage
and appreciation of melo-melo pearls
The melo-melo pearl
became a symbol of perfection in Buddhist thought
The existence of melo-melo pearls originating from
the bailer volute had been known and appreciated by ancient cultures and
civilization of the Southeast Asian nations, such as China, Vietnam,
Cambodia, Japan etc. The perfectly round fiery orange pearl, with its
shimmering flame structure, naturally beautiful, a gift of nature, that
did not require man's intervention, became closely associated with the
Buddhist philosophy, that had very large following in this region. The
pearl became a symbol of perfection in Buddhist thought, and became one
of the eight precious emblems of the Buddha. Both the bailer volute
shell and the pearl became objects of veneration by Buddhists.
The dragon and
flaming-pearl motif became a favorite motif of emperors symbolizing the
emperor striving to achieve the noble virtue of perfection.
The
ancient Chinese, Japanese and Vietnamese believed that pearls were
created from droplets that fell from the dragon in the heavens, on the
sea, that were taken in by the open shells of clams, oysters and
sea-snails. These droplets of water from the heavens grew into pearls,
nourished by the moonbeams that fell on the seas at night time. Thus,
the fiery melo-melo pearl with a flaming tail and the dragon, became a
ubiquitous motif of the decorative arts of the Chinese and Vietnamese,
appearing in paintings, textiles and ceramics. The dragon in these
artistic expressions symbolized the emperor, who was shown pursuing the
pearl, the symbol of perfection, a goal that every emperor strived to
achieve. Thus the dragon and flaming- pearl motif became a favorite motif
of the emperors, which was used freely in all artistic expressions and
even on the imperial robes. The melo-melo pearls being sacred objects,
were never drilled or strung as beads, but preserved as objects of
devotion. The Emperors of Vietnam valued the pearl so highly that they
send their ships to search for these rare beauties in the waters of the
Halong Bay and the South China Sea.
Chinese Dragon and Flaming Pearl Motif on a banner
The Rarity of Melo
Melo Pearls
Melo-Melo pearls are
rare but precise figures of their frequency of occurrence not available
Melo melo pearls are one of the rarest natural pearls
in the world. Gem-quality purple quahog pearls are believed to be
the rarest natural pearls in the world, whose probability of occurrence
had been calculated to be around 1 in 2 million. Please go to the
following webpage for the computation of the probability of quahog
pearls :-
The Golash quahog pearl brooch - the Pearl of Venus.
Melo melo pearls are less rarer than purple quahog pearls. However,
computing an approximate probability for the pearls occurrence is
difficult because of the lack of statistics. Recently, after extensive
trawler harvesting of the Melo melo sea-snail in the South China Sea off
the coast of Vietnam, as a source of food not mainly for the
Vietnamese markets, but for export to China, significant quantities of
the rare pearl appeared as a by product of the industry. However, no
precise figures were given for the frequency of occurrence of melo-melo
pearls in these waters. Sea-snail fisherman gave a vague figure of one
in several thousand for these pearls.
Melo-Melo pearls were
once extremely rare not because of their rarity of occurrence inside the
snails, but because of the difficulty of their harvesting from the deep
waters of the ocean
For quahog pearls the frequency of occurrence of a
purple pearl was given as one in 100,000, out of which only one in 20
was said to be of gem-quality, giving a probability of 1/100,000 x 1/20
= 1/2,000,000. This is an extremely rare occurrence, and purple quahog
pearls are considered to be the rarest of all natural pearls. In the
case of melo-melo pearls the pearls were once extremely rare not because
of the rarity of their occurrence inside the snails, but because of the
difficulty in harvesting the sea-snails from the deep waters of the
ocean, which was sometimes as deep as 70-100 meters. The countries of
Southeast Asia did not have the technology to harvest sea-snails at such
depths.
Melo-Melo pearls were
largely unknown to the west until recently. G.F. Kunz's "The Book of the
Pearl" published in 1908, had no reference to the pearl
Thus, the beautiful melo-melo pearls largely remained
unknown to the west in ancient times and until the recent past. Even
George Frederick Kunz's famous publication of 1908, "The Book of the
Pearl" the most authoritative book on the subject of pearls for a long
period, had no reference to the rare melo-melo pearls of Southeast Asia
!
In Burma, at one time
children played marbles with melo-melo pearls, showing the pearls were
not so scarce at that time
In Burma, in the coastal villages, where originally
only a few people knew about the value of melo-melo pearls, children
used these pearls to play marbles. The fact that the pearls were used as
marbles by children perhaps gives an indication of their availability at
one time in Burma, and shows that melo-melo pearls were not so scarce at
that time.
An episode in Vietnam
that lends strong evidence for the extreme rarity of melo-melo pearls -
the story of the cook who processed and cooked sea-snails for almost
fifty years but never found a melo-melo pearl
In May/June 2009 GIA Field Gemologists Vincent
Pardieu and his companions Jean Baptiste Senoble and Kham Vannaxay of
France, Lou Pierre Bryl of Canada and David Bright of USA, undertook a
GIA Laboratory Field Trip to Vietnam in order to visit and collect
specimens from mines in Vietnam, producing ruby, sapphire and spinel.
During this trip they also took the opportunity to visit the most
important melo-melo pearl trading center in Vietnam, the Cat Ba Island
in North Vietnam, to which all trawlers fishing the Melo melo sea-snail
from all around Vietnam headed, to dispose of their catches. Dealers in
Cat Ba purchased the harvest of sea-snails from the fisherman, which
were later exported to China, where there was a great demand for its
meat.
While at Cat Ba, Vincent Pardieu and his companions
visited the port area and the sea front where many hotels. restaurants
and tourist shops were located. They found that only one restaurant in
Cat Ba offered melo sea-snail dishes in its menu, and a live sea-snail
was kept in a fish tank at the entrance to the restaurant. The owner cum
cook of the restaurant offered to cook the sea-snail for the visitors
with green bananas and spices, which they accepted. The visitors made
friends with the cook, and explained to him the purpose of their visit.
The cook who had been in the business for nearly fifty years, cooking
thousands of melo sea-snails during his life time, was surprised to hear
that there were occasional pearls inside the sea-snail. He confessed
that during this long period of handling and cleaning sea-snails he had
never come across a pearl inside any snail. In fact the cook said that
this was the first time he was hearing that there could be rare and
valuable pearls inside these snails. If what the cook had told the field
gemologists from the GIA was the real fact, which obviously is the
case, as there was no reason for him to hide the fact that he had
discovered a melo-melo pearl from the sea-snails, the story lends strong
evidence for the extreme rarity of these pearls.
Mr Duc, the former
Vietnamese navy diver who during his lifetime had seen thousands of Melo
melo sea-snails but only one melo-melo pearl, another indication of
their true rarity.
While at Cat Ba, Vincent Pardieu and his companions
also met Mr. Duc a Vietnamese man in his fifties who was a former navy
diver, who said that his friend Mr. Tchi, a local fisherman discovered a beautiful melo-melo pearl in 1994,
from a sea-snail which he collected, near Trin Hu, Virgin Island, while
he was working as a diver in Ha Long Bay. Mr. Tchi found two large melo
snails in the shallow waters of the Ha Long Bay, closer to the
shoreline. The two of them were surprised by the size of the sea-snails,
which Mr. Duc said was as big as his hat and weighed around 8 kg, too
big for the area where they were discovered, where melo sea-snails were
usually quite small. Mr. Tchi then went about cleaning the sea-snails
before cooking them, when yet another shock greeted them. A large
stunningly beautiful orange round pearl suddenly appeared from inside
the contents of the snail. Mr. Duc said that the pearl was about 2 cm
(20 mm) in diameter, and was glowing, a clear reference to its flame
structure. He said that Mr. Tchi kept the pearl with him, but was not
sure whether he still had the pearl. He further said, that he never saw
or heard about any other melo pearl in Ha Long Bay, during the six years
he served as diver, and since his retirement in 2002. Mr. Duc as a diver
had seen thousands of Melo melo snails, but in his lifetime had seen
only one melo-melo pearl. This gives an indication as to the true rarity
of melo-melo pearls.
The large scale
harvesting of Melo melo sea-snails in Vietnam begins in the early 1990s,
leading to a significant increase in the availability of melo-melo
pearls in the international pearl markets
In the early 1990s the Vietnamese began intensive
harvesting of Melo melo sea-snails using trawlers and dredgers, around
the snail-rich waters of the Spartly and Paracel archipelagos in the
South China Sea, the Back Long Vi Island in the Ha Long Bay, and the Phu
Quoc Island near the Cambodian border. The dredges used by trawlers are
bottom-towed gear, consisting of a metal frame with a blade or teeth to
dig into the sediment and extract the shelled mollusks, and a mesh bag
to collect the catch. Hydraulic dredges that shoots jets of water, onto
the seabed to lift out the target species have also been developed. Even
though the use of dredges had facilitated access to sea-snails living
70-100 meters in the sub-littoral zone, their use had caused
considerable damage to the benthic zone, such as changes in structure,
nature and chemical composition of the substrate, and the
de-stabilization of the benthic eco-system.
The intensive trawler fishing of sea-snails in the
1990s and later from 2000 to 2009, had resulted in a considerable
increase in the availability of melo-melo pearls originating from
Vietnam, in the pearl markets of the world. However, marine biologists
have expressed the view that continued intensive trawler fishing, causing
damage to the sea-snails ecosystem, would decrease recruitment, and
drastically deplete sea-snail resources, rendering future exploitation
totally uneconomical and unsustainable. This seems to have happened
already, as reflected both by decreased harvests and the decrease in
size of the sea-snails caught. The average life span of a melo-melo
sea-snail is not known exactly, but believed to be several decades. Thus
even if there is sufficient recruitment, for snail populations to reach
normal levels and sizes would take several decades.
How melo-melo pearls
are formed ?
The formation of the
pearl is a natural reaction to the lodging of an irritant in the mantle
tissues
Non-nacreous melo-melo pearls are formed in a manner
similar to pearl formation in other shelled-mollusks such as oysters,
mussels and clams. The formation of the pearl is essentially a reaction
to the entry of an irritant into the mantle tissues, or an internal
organ such as the gonads of a shelled-mollusk. The irritant can be a
parasite, damaging debris or waste material. According to the
Gemological Institute of America, the very rare melo-melo pearl is most
likely the result of an intruder. The shell's wide aperture, nearly as
long as the shell itself, may perhaps facilitate the entry of the
irritant, which eventually lodges itself in the mantle tissues of the
snail. The mantle is responsible for the creation, maintenance,
coloration and modification of the gastropod shell. The shell forming
substances such as conchiolin and calcium carbonate are secreted by the
cells of the mantle. The same substances are laid around the irritant to
form the pearl. However, the crystalline form of calcium carbonate that
is incorporated in the pearl is mainly calcite and not aragonite. The
calcite microcrystals are laid as needles and do not scatter light waves
like aragonite platelets. Hence the lack of iridescence in these pearls.
The calcite microcrystalline needles are associated to form bundles of
fibers, whose arrangement and alignment causes a type of chatoyancy
known as "flame structure."
The size and age of
the pearl is related to the size and age of the snail
The pigment secreting cells in the mantle that was
responsible for the coloring of the shell, also secretes the same
pigments that are incorporated into the conchiolin (protein) layers of
the pearl. It appears that the size and color of the melo-melo pearl is
determined by the size and the lip color of the parent sea-snail. A
frequent observation that has been made is that the largest melo-melo
pearls usually appear in the largest sea-snails. This is clearly linked
to the age of the snail, an older snail being fully developed is much
larger than a younger snail which is not fully developed. Likewise the
chances of a pearl growing inside an older snail being fully developed
is much greater than a pearl growing inside a younger snail. Thus the
age of the pearl is related to the age of the snail. Therefore, some of
the large melo-melo pearls that have been discovered from very large
snails, must be as old as the snail themselves, which necessarily means
they are several decades old.
The site of
development of large perfectly spherical melo-melo pearls are the soft
tissues of the mantle and the visceral mass
Another interesting feature that has been observed in
many melo-melo pearls, apart from their extraordinary sizes, is their
perfectly round or spherical shape, the most desired shape for pearls.
For a pearl to develop into a perfect sphere, its development has to
take place in a fairly soft tissue, where equal resistance is offered to
the expanding pearl from all sides. If the resistance offered on one
side is greater than the other sides, the resulting pearl could acquire
any shape other than spherical, such as near-round, oval, drop-shape,
baroque etc. Except for the muscular foot which is quite tough, other
parts of the snails body, such as the visceral mass and the mantle,
situated inside the shell are soft, and may provide the ideal location
for the development of spherical pearls.
Characteristics of
melo melo pearls
The melo-melo pearls with a combination of desirable
characteristics, such as the intense orange color, spherical
shape, unique flame structure, porcellaneous luster, durability and
above all their natural provenance, has become one of the rarest and
most sought after pearls in the world today. The following is an account
of the natural characteristics of these pearls considered under
different sub-headings.
1) Non-nacreous pearls:- Melo-Melo pearls are non-nacreous pearls
like conch pearls and are also produced by a marine gastropod like conch
pearls. However the families to which the gastropods belong are
different. While the Melo melo sea-snail belong to the Volutidae, the
Strombus gigas sea-snail that produces conch pearls belong to the
Strombidae. Likewise the habitat in which the two snails are found are
also different. While the natural habitat of the Melo melo sea-snail is
the Indo-Pacific region, the natural habitat of the Strombus gigas
sea-snail is the tropical zone of the Western Atlantic Ocean from
Bermuda to Brazil, that also includes the Caribbean and the Gulf of
Mexico.
2) Luster :-
Being non-nacreous melo-melo pearls do not have the luster and
iridescence of nacreous pearls. But, they still have a porcelain-like
luster, which is known as a "porcellaneous luster." Both the lack of
iridescence and brilliant luster are associated with the type of
crystalline calcium carbonate deposited, and the structure and
arrangement of the calcium carbonate microcrystalline units.
3) Flame Structure :-
As if to compensate for the lack of luster and iridescence nature has
gifted melo-melo pearls with another unique and attractive feature,
known as the "flame structure," whose presence gives a fiery flame-like
shimmering appearance to these pearls, particularly to the orange
variety of the pearl. This spectacular "flame structure" sometimes
surpasses the beauty of most low-quality nacreous pearls. The flame
structure is also associated with the arrangement of the
microcrystalline calcium carbonate fibers, similar to the "chatoyancy"
in beryls and other gemstones caused by rutile fibers.
4) Color :- The
colors of melo-melo pearls is related to the color of the shells. The
shell color of the bailer volute varies from beige (pale-sandy color) to
orange, and brown. The interior of the shell is yellow to cream
color. Thus the pearls produced by the bailer volute can have three
basic colors yellow, orange, and brown or different shades
of these colors or a mixture of two of these colors, such as light,
medium and dark yellow; light, medium and dark orange; light, medium and
dark brown; light, medium and dark yellowish-orange and orangish-yellow;
light, medium and dark yellowish-brown (tan) and brownish-yellow; light,
medium and dark orangish-brown and brownish-orange. The commonest and
most-beautiful colors are the different shades of orange. White is also
a very rare color in which melo-melo pearls sometimes appear. Another
very rare color that has been reported is reddish-orange.
The pigments or biochromes associated with these
colors are secreted by special secretory cells in the mantle tissue. The
color of melo-melo pearls like the conch pearls are affected by
ultra-violet radiation, and jewelry set with such pearls are ideally
suited for evening wear.
5) Shape :-
Melo-Melo pearls occur in a range of shapes, such as spherical or round,
near-spherical or near -round, oval or egg-shaped, and baroque or
irregular shape. The commonest shape in melo-melo pearls are spherical
and near-spherical, although perfectly spherical shapes may be extremely
rare.
6) Size :- The
size of melo-melo pearls varies with its age and is closely related to
the size of the shell from which it was derived. Usually larger shells
that are older produce larger pearls. The size of the pearls can vary
from a few millimeters to around 35 mm. The largest pearl on record,
which has the size of a ping-pong ball, has a size of 37.58 mm to 37.97
mm along different diameters, and has a record weight of 397.52 carats.
In keeping with a size of a few mm to around 35 mm, the weight of
melo-melo pearls also vary from a few carats to over 300 carats.
7) Hardness :- The hardness of melo-melo pearls is
approximately 5 on the Mohs scale. This compares with a hardness of 2.5
to 4.5 for natural nacreous pearls. Thus melo-melo pearls are
harder than other natural pearls
8) Refractive Index :- the refractive index of melo-melo pearls vary from 1.51 to 1.64
9) Natural Provenance :-All
melo-melo pearls are necessarily natural in origin. This is obviously
because all attempts to culture these rare beauties have so far proved
unsuccessful.
10) Effect of u-v rays on
the color of melo-melo pearls :- The color of melo-melo
pearls like all other organic gems are affected by
ultra-violet radiation, and jewelry set with such pearls are ideally
suited for evening wear. However such effects become apparent only after
prolonged exposure over many years. The fading of color is caused by the
destruction of color causing pigments by u-v rays in sunlight. The color
of conch pearls are also affected by u-v radiation. Even black Tahitian
pearls can be affected, as reported by G. F. Kunz in his book "The Book
of the Pearl" in reference to a black pearl that lost its color and
luster after exposure to sunlight in a jeweler's shop window.
The surge in
popularity of melo-melo pearls
The recent worldwide
popularity of melo-melo pearls attributed to the efforts of Benjamin
Zucker, the New York gem dealer and writer
Although melo-melo pearls had been known and
appreciated in Southeast Asia from time immemorial, its sudden worldwide
popularity is of recent origin, attributed to a New York gem dealer and
writer Benjamin Zucker. The intensive trawler harvesting of Melo melo
sea-snails began in early 1990s, and significant quantities of melo-melo
pearls were discovered from the sea-snails. In 1993, a collection of 23
deep-orange melo-melo pearls, perhaps purchased by a Swiss dealer
from the Vietnamese was shown to Benjamin Zucker for assessment and
evaluation. In fact the dealer is reported to have left the pearls with
Zucker for further intensive studies. Zucker got in contact with his
friend Kenneth Scarratt, of the Gemological Institute of America, who
later became the Director of the GIA in Bangkok. Scarratt with his vast
knowledge and experience with pearls of all kinds, and author of
the book "Pearl and the Dragon" the first extensive gemological report
on melo-melo pearls, identified the pearls immediately as Vietnamese in
origin. Zucker who was also a pearl enthusiast, and was interested in
finding out more about these rare beauties, got together a small team of
gemologists, scholars and writers, who visited Vietnam, with a view of
documenting all available facts about these pearls, including their
origin and the habitat of the mollusks in which they develop. Zucker's
historic visit to Vietnam was the inspiration for a 1997 article on
melo-melo pearls in the Smithsonian magazine, which gave a big boost to
the popularity of these pearls.
Record price set by a
fiery orange melo-melo pearl at a Christie's auction in Hong Kong in
November 1999
It is believed that Zucker's explorations in Vietnam
and the subsequent Smithsonian article, set the stage for the record
price registered for a melo-melo pearl at a Christie's auction in Hong
Kong in November 1999. The near-spherical fiery orange pearl with
dimensions of 23.0 x 19.35 mm, fetched a record price for a single
pearl, USD 488,311. The pre-sale estimate of the pearl was placed only
between USD 20,000 - 30,000. The unexpected strong bidding for the pearl
resulted in a hammer price 16 times higher than the upper pre-sale
estimate, a trend that was attributed to Zucker's work on the
pearl.
A second melo-melo
pearl sold by Christie's Hong Kong in April 2000 realizes a lower but
still attractive price
In April 2000, Christie's of Hong Kong put up another
near-spherical and fiery orange melo-melo pearl for sale. The pearl was
larger (31.70 x 31.26 mm) and more beautiful than the pearl that set the
price record in November, 2009. Accordingly, in keeping with the prices
realized at the first auction, the auction house placed a higher
pre-sale estimate of USD 150,000 to 200,000 on the pearl. However, the
price realized at the auction was USD 277,272, higher than the upper
pre-sale estimate, by USD 77,272.
The after-effects of
the two record-breaking auctions of melo-melo pearls
Attempts to
increase production of melo-melo pearls to cash in on their popularity
The extraordinary prices recorded by two melo-melo
pearls at Christie's auctions held in Hong Kong, in the years 1999 and
2000, was good news for the Vietnamese pearl prospectors, and all other
countries in the Indo-Pacific where the Melo melo sea-snail was found
and harvested. In Vietnam, the exploitation of the Melo melo sea-snail
continued with renewed vigor resulting in a considerable increase in
production of melo-melo pearls. Burma, Thailand and Cambodia took a keen interest in
taking a fresh look at their sea-snail resources. In Burma fishing
trawlers known as "Wa-lat" or "Gar" began extensive exploration of the
muddy bottom of the seas at depths of 30m to 50 m, along the Arakan
coast and in the southern region of Dawei (Tavoy) , the Mergui
Archipelago, and Kawthaung in the Andaman Sea, near Thailand. The result
was significant quantities of melo-melo pearls entering the pearl
markets. In Thailand Melo-melo sea-snails were being harvested as a by
product of the crab-fishing from the Gulf of Thailand. However,
the production of melo-melo pearls was not significant.
The entry of
melo-melo pearls from old collections into the markets
.
Apart from that melo-melo pearls held in private collections in Asia
made their appearance in the pearl markets. The owners of these
collections were keen on cashing in on this unexpected boom in prices.
The result was a glut of melo-meo pearls in the markets of all sizes,
shapes and colors, but not necessarily of the highest quality. The
ultimate result of this chain reaction was a depression in prices, from
hundreds of thousands to tens of thousands of dollars
The enhanced
prices for melo-melo pearls gave a boost for research activities in
culturing these rare and unique fireballs of nature
The incentive provided by enhanced prices for melo-melo pearls was so great, that
countries began investing heavily on research for the culturing of Melo
melo sea-snails and melo-melo pearls. One of the pioneers in this research
was Suraphol Chunhabundit, marine biologist at the Chulalongkorn
University in Bangkok, working at the Sichang Marine Science Research
and Training Station in the Chonburi Province in the Gulf of Thailand.
It is reported that he had achieved partial success in culturing
melo-melo pearls by implanting Pigtoe mussel nuclei into
sea-snails. However, details of his research has not been published, and
the research was still continuing when funding for his project was
terminated abruptly. Efforts in culturing not only melo-melo pearls
inside the Melo melo sea-snail, but also conch pearls inside Stombus
gigas had met with limited success in other parts of the world. The
primary reason for this failure is the difficulty in accessing the
pearl-producing area of the snail for implantation due to the peculiar
anatomy of the univalve gastropods.
Marketing of
melo-melo pearls
Apart from the regular auctions held by two of the
most prominent international auction houses, Christie's and Sotheby's in
Hong Kong, where top-quality melo-melo pearls sometimes appear, and
fetch quite attractive prices, melo-melo pearls produced in Southeast
Asia, also eventually find their way to another regional marketing
center for all types of gemstones. viz. Bangkok in Thailand, where these
rare beauties are auctioned regularly and go to the highest bidder.
The future of the
melo-melo pearl ?
Vietnam is the main producer of melo-melo pearls in
the world today, followed by Burma. The exploitation of melo-melo
sea-snails with renewed vigor, following the popularity of melo-melo
pearls, is undoubtedly going to have a serious impact on their
populations. It is reported that already in Vietnam the snails are
becoming scarcer and smaller in size. This is the obvious result, due to
the long life-span of the snails, and the reduction in the recruitment
of young snails. Recruitment declines when the adult populations are
drastically reduced by over fishing. Even if there was adequate
recruitment, if sufficient time is not given for the snails to reach
their maximum size and potentialities, the size of the snails caught
will necessarily be small, and any pearl developing inside will also be
small, as it is an observed fact, that the size of the pearl depends on
the size of the snail. Thus, if exploitation of sea-snail resources are
not carried out in a planned and methodical way, giving sufficient time
for adult populations to re-establish themselves, the future of the
natural melo-melo pearl industry will be very bleak indeed! The pearls
will get scarcer and dearer and eventually disappear altogether from the
pearl markets of the world.
This was exactly what happened to the natural pearl
industries in Venezuela, Columbia and Panama during Spanish colonization
of these countries. Pearls that were discovered by Christopher Columbus
towards the end of the 15th-century was totally exploited and exhausted
in about 150 years, and the industry abandoned in the mid-17th century.
Another instance from history comes from the Gulf of Mannar, in Sri
Lanka (Ceylon), one of the most ancient sources of natural pearls in the
world, where sustainable exploitation using traditional methods
continued for over 2,000 years, without any depletion of resources, but
after colonization by the Portuguese (1505-1656), Dutch (1656-1796) and
the British (1796-1948), and the intensive exploitation that followed,
destroyed the natural pearl industry in 1906, never to recover again,
the final death blow being given by Mikimoto.
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)
Queen Mary Conch Pearl Brooch
2)
Susan Hendrickson's Conch Pearls
External Links :-
1) Melos and their Pearls in Vietnam - May/June 2009-
Concise Field Report, Volume 2, Part 1. Vincent Pardieu, GIA Laboratory,
Bangkok.
References :-
1) Melo Pearl - by David Federman,
www.modernjeweler.com
2) Pearl That Really Aren't - The Conch and the Melo
Melo "Pearl" - by Amy Hourigan, Graduate Pearls Program, GIA.
3) Lot 2390 - An Impressive Melo Pearl, The Dragons
Flaming Pearl - Bonhams & Butterfields auction 2005.
4) Melo Pearls From Myanmar - Han Htun, Bill Larson,
Jo Ellen Cole -www.palagems.com
5) Report on cultivation of Melo melo pearls in Thailand, September 2001
- www.parels-ael
6) Nature and Importance of Circalittoral Faunal Turfs (CFTs) - www.ukmarinesac.org
7) Marine Habitats - Malta Environment and Planning Authority -
www.mepa.org.mt
8) Littoral Zone - From Wikipedia, the free encyclopedia
9) Gastropoda -
www.manandmollusc.net
10)The Pearl Book - Natural, Cultured & Imitation Pearls -
Terminology & Classification - CIBJO, The World Jewelry Confederation.
11) Melo melo - From Wikipedia, the free encyclopedia
12) Baler Volute, Melo melo, Family Volutidae - Wild Fact Sheets. www.wildsingapore.com
13) Melos and their Pearls in Vietnam - May/June 2009- Concise Field
Report, Volume 2, Part 1. Vincent Pardieu, GIA Laboratory, Bangkok.
