Gemstone and Pearls Guide
PRECIOUS GEMSTONES
Only three colored gemstones are considered precious. These are the emerald,
sapphire and ruby, which have retained their prized positions among jewels due
to their extraordinary colors and extreme rarity. Precious gemstones with good
color and large size are very hard to come by. Because of their rarity, it is
common to use stones with inclusions and blemishes in jewelry.
SEMI-PRECIOUS GEMSTONES
A semi-precious gemstone includes any gemstone other than sapphire, emerald or
ruby. The value of semi-precious gemstones can vary depending on the
availability of the mineral; natural black opal, for example, is hard to come by
and more valuable than most other semi-precious stones. As a rule, however,
semi-precious stones are always more plentiful than precious stones. That makes
it easier to find large, well-colored, very clean stones appropriate for
jewelry. In addition, the wide range of colors available makes semi-precious
stones the choice for people who want to create their own look with their
jewelry.
Synthetic or "lab-created" stones are grown using the same ingredients as the
natural stones. They are chemically identical to natural stones, but more
affordable, and its easier to get a large, well-colored lab-created gem than a
natural one. Lab-created gems frequently have fewer "inclusions," the internal
flaws common in precious gems. With technical advances, many high quality
lab-created stones can only be differentiated from a natural by a trained
professional. Almost any gem can be made in a lab, but the precious gems -
emeralds, rubies and sapphires - are the most common.
PEARLS
A pearl is formed when an irritant, such as sand or a parasite, becomes lodged
in the shell of an oyster. The oyster deposits layers of a semi-translucent
crystalline material called "nacre" around the intruder, where it builds up in
layers like the rings of a tree. This process of building up can continue for
years, resulting in a pearl. In nature, pearls take many years to develop and
often have irregular shapes, ranging from slightly off-spherical to twisting,
bulging shapes called "baroque." In any shape, natural pearls are rare and very
costly.
Because natural pearls are so rare and difficult to recover from the ocean's
depths, man invented the technique of culturing salt and freshwater pearls from
oysters and other mollusks carefully seeded with irritants similar to those
produced by nature. The painstaking effort of culturing is one of the most
dramatic examples of man's quest to coax beauty from nature.
Due to demand for perfectly matched white pearl strands, cultured, fresh and
saltwater pearls are often bleached to achieve a uniform color. They may also be
polished in tumblers to clean and improve their luster.
Pearls are most commonly thought of as white, but they are actually produced in
many colors, including gold, yellow, champagne, pink, peach, lavender, gray, and
black.
Cultured pearls are rated on five different qualities:
Luster and orient: Luster is the sharpness and intensity of reflections on the
pearl's surface, and orient is the iridescent colors one sees within the pearl.
The higher the luster and orient, the more valuable the pearl.
Color: Color describes both the main color (usually white, black or yellow) and
the undertone (often pink, rose, or even green.) In addition, pearls can be dyed
any shade to meet personal preference.
Cleanliness: Describes how many imperfections are found on the surface of the
pearl. Some imperfections are expected on all real pearls, natural or cultured,
but the fewer and less noticeable they are, the better.
Shape: In general, spherical pearls are the most prized. However, it is common
to find small imperfections of shape, which can sometimes be desirable as long
as they are symmetrical. For example, teardrop shaped pearls are often used in
earrings and pendants.
Size: Cultured pearls are sold by diameter, measured in millimeters. In general,
larger cultured pearls are rarer and more costly. Price rises significantly with
the size of a pearl.
In addition, one should look at how well matched pearls are when combined in
jewelry, such as on a necklace or in earrings. You should look for pearls that
are essentially the same size, color, shape and luster. Keep in mind that the
more well-matched pearls there are in a piece of jewelry, the higher the cost.
That's why pearl earrings cost more than two individual pearls.
How to Care for your Gemstone
and Pearls
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