Do you use pearls in
your jewelry designs?Â Need a better
understanding of pearls and how they growâ€¦
How Pearls are Formed
A pearl is a natural gem created by a living
organism. When a foreign object is introduced into a mussel or oyster the
animal coats the irritant with a substance called Layers of nacre build up to make a
Most wild, natural pearl producing oyster beds have vanished due to
over-fishing, oil drilling and pollution. Today, the world's most beautiful
pearls are cultured.
Cultured pearls share the same properties as wild pearls. The difference is
that a technician opens the shell and inserts the irritant which stimulates
have a round shell bead (traditionally from an
American freshwater mussel) grafted in as the irritant. This is called
'nucleating'. Oysters are suspended in water from rafts and at risk from
typhoons, parasites, predators and algae.
have a small piece of mantle tissue (nacre
producing tissue from another mussel) introduced as the irritant. This tissue desiccates
leaving a solid pearl. Mussels are farmed in inland lakes and rivers.
Harvesting pearls is a
time consuming business. Of the millions of oysters and mussels seeded each
year, only a proportion (maybe just 50%) will survive to bear pearls. Of these,
many will not produce pearls of a marketable quality.
Each pearl must be sorted by size, shape, color, lustre and blemish. Â Â Then they need to be drilled and matched for
stringing - a skilled and laborious task. To find 50 perfectly matched
high-quality pearls for a 16 inch necklace a pearl processor may have to sort
Pearl Shapes and Colors
Pearls come in a variety of shapes, colors and
sizes. Round pearls traditionally command the highest prices but it's worth
remembering that wild pearls were rarely round. Different shapes can give you a
lot of pearl without breaking the bank.
are rarely perfect spheres unless they are of gem quality or imitation. The
longer the pearl remains within the oyster or mussel the more chance there is
of it developing an irregular shape. Very large round pearls are uncommon - and
expensive. Even pearls nucleated with a shell bead have a hard time keeping
their shape as they grow.
off-round is used to describe pearls which are 'roundish' to the eye but
have a slightly oval or flattened shape. They can still have excellent
qualities in terms of lustre or lack of blemish.
Oval Pearls are sometimes known as rice pearls. It comes from the very early days of
Chinese freshwater pearl production when large numbers of low quality pearls
entered the market and were derided as 'rice-crispies' after the cereal.Â Â Oval pearls can form when two pearls in the
same mollusc join together.
Most natural wild pearls were off-round or baroque (a general term for
irregular shape).Â Bead nucleated pearls
(pearls seeded with a round shell bead) may develop a tail on one side.Â The most valuable baroque pearls are South
Sea and Tahitian. Due to the length of time under cultivation a high percentage
of the pearl harvest is baroque.
So-called because of their shape - round on
one side and flat on the other.
Keishi Pearls are accidents which happen when the mollusc
rejects the nucleus and grows a 'free form' pearl.
come fromÂ from Lake Biwa, a large freshwater lake near Kyoto in
Japan. This was once the focus of the Japanese freshwater pearl industry. In
the 1980's pearl production ceased due to industrial pollution.
Stick pearls, long natural freform pearls are sometimes called Biwa pearls.Â Technically it is incorrect to call pearls Biwa unless they actually come from Lake Biwa.Â
Biwa became a generic name for all freshwater pearls regardless of their shape.
Pearls come in a variety of colors. Natural colors (white, off white, pink,
grey, â€œblackâ€) are mainly due to the breed of mollusc. Other influences include
diet, water temperature and pollutants. No-one can predict or control what color
pearls will be produced in any hatchery.
Pearls are rarely jet black but blue, green, grey,
aubergine, peacock and more. Green is the predominant color.Â Naturally colored black pearls come from the
pearl farms of French Polynesia (Tahitian pearls) as well as Indonesia and the Philippines.Â
Except for the occasional â€œmutantâ€, there are no natural black freshwater or
Akoya pearls. The majority of 'black' pearls are treated in some way - it
doesn't harm the pearl.
Nacre isÂ crystals of calcium carbonateÂ the same material that the mussels / mollusc use to create their shells.
also called simulated, organic, faux and semi-cultured are made from beads of glass,
ceramic or shell and coated with a varnish or laquerÂ sometimes containing ground fish scales to
mimic the pearl surface.
If you are not sure about your pearls being natural or imitation you can use theÂ 'tooth test'. Gently rub
the pearlÂ against theÂ edge of your top front teeth. Don't bite it.Â A real pearl should feel slightly gritty due
to its crystalline structure. Â An
imitation pearl will feel smooth. This is not an infallible test as tooth sensitivity can change how the "pearl" feels
I hope this helps you with your pearl buying experiance