Gemstones
Beauty. Rarity. Durability. These attributes attract us to colored
gemstones for personal adornment and make gemstones valuable and
precious. Colored gemstones provide the opportunity for uniquely
personal expression.
Beauty
Most colored gemstones derive their beauty from their color –
purples, blues, greens, yellows, oranges, reds. In certain colored
gemstones color occurs naturally. Satisfying hues are intrinsic in some
garnets, for example. In other colored gemstones, the final color
occurs with assistance. For nearly as long as people have worn rubies,
we have known how to treat a rough ruby with heat to obtain a desirable
red color. Not all rubies are heat treated, but the vast majority are.
Gem cutters work to achieve a pleasing and affordable mix of color,
weight (measured in carats), and a safe shape for mounting. During
creation, a gemstone’s size is constrained by nature. For example,
while large and beautiful amethysts are readily available, an
alexandrite of large size is extremely rare.
Sparkle adds to the beauty of a well-cut colored gemstone. The cut
of a colored gemstone describes its shape and how it is fashioned. Some
gemstones, such as opal, are suited to a smooth, rounded surface.
Others, such as sapphire, are more frequently shaped with a precise
series of flat, symmetrical planes, called facets, which make
the most pleasing illumination of the gem’s color. Some cutters today
may also use convex or concave facets, shaping colored gemstone like
small sculptures.
The clarity of colored gemstones contributes to their beauty. Unless
a gemstone is opaque and blocks all light, how light moves through the
gemstone affects its beauty. Some gemstones have few internal
inclusions to interrupt the passage of light, as is the case with most
pieces of tanzanite. Others have characteristic inclusions. For
example, some emerald has a “jardine” (garden), which makes each gem
truly unique.

Rarity
Across time and cultures, people have
adorned themselves with rare gem materials. From pearls and corals
plucked from the seas, to bright colored pebbles found in the soils
settling at the mouths of rivers; from the collection of gemstones
mounted in the breastplate of Aaron as accounted in ancient scripture,
to the historic gemstones mounted in the crown jewels of European
monarchs, we let ourselves be known through the gemstones we choose to
wear. These gemstones are precious because they are rare.
Because of their rarity, gemstones in which color is naturally
occurring are generally more valuable. Many gemstones are treated or
enhanced in some way, such as with heat or safe irradiation, to achieve
the beautiful colors or clarity we desire in the sizes we desire. These
gems, which are less rare, can also be very valuable. Some jewelers
make synthetic colored gemstones available. Synthetic colored gemstones
have all the optical, physical and chemical properties of naturally
occurring gemstones, but they are created in a laboratory rather than
occurring in nature. For some budgets, these synthetic materials are an
acceptable choice.
Durability
A
gemstone’s ability to be fashioned, mounted and worn is a function of
how durable it is – a matter of both hardness and toughness. Some
gemstones, such as sapphire, ruby and garnet, are well-suited to an
active daily life and work well in rings, bracelets or cufflinks.
Others, such as emeralds, pearls and opals call for earring or necklace
mountings to keep them beautifully displayed but out of harm’s way.
Buying Colored Gemstone Jewelry
When buying
colored gemstone jewelry, select what you consider beautiful. Because
of the subtle differences in the tone and hue of the colored gemstone
you are considering, look at several to find the one you prefer. Some
jewelers offer loose colored gemstones and are able to help you create
a personalized mounting. You may prefer to buy a finished jewelry item.
Discuss how you see yourself wearing the piece so that your jeweler can
help you select mountings consistent with your lifestyle. This will
provide the best safeguard for your purchase.
You have the right to know what you are buying, whether yours is a
natural gemstone, an enhanced or treated gemstone, or a synthetic
gemstone. The Federal Trade Commission (FTC) has established guidelines
for the jewelry industry stating that jewelers must disclose any
treatment that is not permanent, that creates special care
requirements, or that affects the gemstone’s value. Likewise, if a
material is synthetic, it must be disclosed. Jewelers of America (JA)
advises its members to disclose all such information, in the belief
that a well-informed jewelry purchaser is a satisfied purchaser.
To give you the information you need, many jewelers provide written
notice at the time you buy a gemstone by way of a note or code
explaining your purchase. This information is written or stamped on the
invoice or on an information card enclosed with your purchase. Be sure
that the meaning of any code is clear to you. It is important to obtain
this information prior to leaving the store, because it affects your
purchase price and will also affect future cleaning and repair as well
as replacement of an insured loss.
A reputable jeweler is your best source for cultured pearls. A
knowledgeable jeweler can explain how to balance a number of quality
and size variables to get the best selection available within a certain
price range. You will be able to evaluate pearls on the basis of the
following criteria:
Note: Your computer screen resolution and color setting may affect
pearl color, lustre and actual sizes as compared to viewing with the
naked eye.
PEARLS
Lustre
The combination of surface brilliance and a
deep-seated glow, the luster of a good-quality pearl should be bright,
not dull. Your reflection should be seen clearly on the surface of a
pearl. Any pearl that looks too chalky or dull indicates low quality.
Surface
Cleanliness of the pearl surface refers to the
absence of disfiguring spots, bumps or cracks. A pearl with a clean
surface will have a higher value than a spotted, bumpy or cracked one.
Shape
Since cultured pearls are grown by oysters and
subject to the whims of Mother Nature, it is very rare to find a
perfectly round pearl. While rounder pearls are more valuable,
asymmetrical, or baroque, pearls have a unique charm and are available
at a more moderate cost.
Color
Rose Silver/White Cream Gold Blue/Gray Cultured
pearls occur in colors from rosé to black. While color is a matter of
preference, rosé or silver/white pearls tend to look best on fair skin
tones, while cream and gold-tone pearls are flattering to darker
complexions.
Size
Measured by their diameter in millimeters, the
average cultured pearls sold today are between 7 and 71/2 millimeters.
Generally, the larger the pearl, the more valuable it will be.
VARIETIES OF CULTURED PEARLS AND WHERE THEY ARE GROWN
Akoya (grown in Japan and China)
Akoya pearls are the
classic cultured pearls of Japan. They are the most lustrous of all
pearls found anywhere in the world. In recent years, China has been
successful in producing Akoya pearls within their own waters. However,
at this time they are unable to produce as brilliant a lustre as high
quality Japanese Akoya cultured pearls.
White South Sea (grown in Australia, Mynamar and Indonesia)
White South Sea cultured pearls are grown in large tropical or
semi-tropical oysters in Australia, Mynamar, Indonesia and other
Pacific countries. They generally range in size from 10mm to 20mm and
command premium prices because of their relative rarity and large size.
South Sea Black (grown in French Polynesia)
South Sea black cultured pearls are grown in a variety of large pearl
oysters found primarily in French Polynesia. Their beautiful, unique
color and large size can command very high prices.
Freshwater (grown in Japan, China and the United States)
Freshwater pearls are easily cultivated from freshwater mussels rather
than saltwater oysters. They are produced in great abundance, and are
therefore generally the most moderately priced of all cultured pearl
varieties. Their unique shapes and gentle pastel colors make them
perfect gems for those on a budget.
Mabe Pearls (grown in Japan, Australia, French Polynesia, Indonesia, and the Philippines)
Mabe pearls are hemispherical cultured pearls grown against the inside
shell of any oyster rather than within the oyster's body. They are
generally used in ring, earring and pendant settings which cover their
flat backs or reverse side.
Keshi Pearls (grown in Japan, Australia, French Polynesia, Indonesia, and the Philippines)
Keshi pearls, though not nucleated cultured pearls, are created by
accident as a result of the sulturing process and these must be
considered cultured pearls. Their unusual shapes and sizes are best
used in unique jewelry designs.