26
The pearl is the only
gemstone which is
grown inside of a
living organism.
How are pearls formed & what
are the different kinds of pearls?
Pearls of Wisdom
FRESHWATER
PEARLS
VS.
SOUTH SEA
PEARLS
Freshwater pearls are
harvested in mussels that live
in lakes and rivers, while South
Sea pearls are harvested in
oysters that live in the Ocean.
~
Freshwater mussels can grow
up to 40 pearls in one mussel.
This is the standard, smaller
round pearl you probably
are used to identifying as a
freshwater pearl. South Sea
oysters only grow one pearl
per oyster.
~
A Freshwater pearl harvest
usually takes 6 months to 4
years to develop the pearls,
where a South Sea pearl
harvest will take 5 years to 25
years to develop one pearl!
~
Fresh water pearls come in
unusual colors of lavender,
peach, grey and white, while
Salt Water pearls come in
exotic shades of gold, silver,
black, white, blue, green and
brown.
Pearls are formed within oysters or
mollusks when a foreign substance
(most often a parasite - not a grain of
sand) invades the shell of the mollusk,
entering the soft mantle tissue, and picking
up epithelial cells. In response to the
irritation, the epithelial cells form into a
sac (known as a pearl sac) which secretes
a crystalline substance called nacre, the
same substance which makes up the
interior of the oyster’s shell, which builds
up in layers around the irritant, forming
the pearl.
Natural pearls have always been
extremely rare and valuable.
In a completely natural state, only a
very small percentage of oysters will
ever produce a pearl at all. As pearls
have been a prized gem by much of the
world’s population for thousands of years,
this need has led to the development
of cultured pearls. In the late 19th and
early 20th centuries, several Japanese
researchers discovered a method of
producing pearls artificially. The technique
involves inserting a foreign substance, or
nucleus, into the tissue of the oyster or
mollusk, then returning the creature to
the sea and allowing the resulting cultured
pearl to develop naturally.
What Are Fresh Water
Coin Pearls?
Lake Biwa was once world renowned
for producing high-quality freshwater
pearls produced by the Hyriopsis schlegeli
(Biwa pearly) mussel. However, in the
mid 1970’s pearl farming came to a
halt due to pollution in this lake that
was once synonymous with freshwater
pearls. In 1998, Isaac & Orna were
able to purchase the last 633 kilos of
natural Biwa coin pearls from a Japanese
company. There are other coin pearls
in existence today which come
from other areas - but Biwa
pearls are special for a variety
of reasons:
~ Biwa pearls have a higher
luster than other coin or button
pearls.
~ Biwa pearls come out flat because the
mussel that they grow in is flatter than a
normal mussel.
~ Biwa pearls only come in shades of
white, cream, peaches and pink.
~ Biwa pearls develop in the shape of
the nucleus. Most of the nucleus’ that
were used were round, to develop round
pearls. However, if you have a pearl that
is in the shape of a heart or square, it is
because the nucleus was in the shape of a
heart or square.
DETERMINING THE QUALITY OF A PEARL
The quality of pearls are determined by
the same factors as diamonds:
Size The bigger the pearl - the longer it took
to grow.
Clarity The luster & the smoothness
ShapeThe most desirable shape in the past
has been round. However, most people today
are looking for unique, natural shapes - as if
they were looking for a “natural cut” diamond.
Because of this, Baroques have become
almost as valuable as rounds.
Color This is determined more by the
customers’ preference than anything else.
The rarer the color - the more desirable.