Four Methods
Thinking of buying pearl
jewelry? A few simple tests can help you determine whether your pearl item is a
fake or real, cultured pearl or real pearl, plastic or real, man-made pearl or real pearl? Learn how to
look and feel for the signs of a real pearl today and you'll never need to
worry about falling for imitations again.
Method 1 of 4: Touch Tests
Rub the pearls against your
front teeth. Hold one or two pearls between your thumb and forefinger and press
them gently into the biting edge of your front teeth. Rub them against your
teeth with a side-to-side motion. A real pearl will usually have a slightly
rough or gritty texture from tiny scale-like imperfections in its outer layers
of nacre. Fake pearls made from glass or plastic will usually almost perfectly
smooth. You may want to brush your teeth before attempting this test to make
sure they're clean. Food residue from a recent meal can give false results.
Step 2
Rub the pearls against each
other. Hold a few pearls in your fingers and gently rub them against each
other. Feel for the slight sensation of friction. Real pearls will usually
generate a little friction when they rub against each other because their outer
layers of nacre are not perfectly smooth.[2] Fake pearls, on the other hand,
often have smooth coatings and will usually glide past each other when rubbed
together.
Take a close look at your
hands after this test. When two pearls rub against each other, their outer
layers often erode a small amount. If you notice a fine, powdery, white residue
after rubbing your pearls, this is probably powdered nacre — a sign that the
pearls are real.
Step 3
Check whether the pearls are
perfectly round. Because they're products of nature, every real pearl is
slightly different, just like snowflakes or fingerprints. Most pearls won't be
perfect spheres — they'll usually be slightly oblong or have minor defects. If
your pearls look perfectly round to you, there's a good chance they're
artificial.
It is possible for real
pearls to be perfectly round. However, examples of these are very rare and
usually fetch a high price.
Not sure whether a pearl is
perfectly round or not? Try carefully rolling it on a flat surface. Imperfect
pearls won't consistently roll in a straight line.
Step 4
Feel for coolness to the
touch. For this test, you'll need a few pearls that have been sitting out — not
ones you've been wearing. Hold the pearls in your hand and concentrate on the
way they feel against your skin. Real pearls should feel noticeably cool for a
few seconds before they warm up. The feeling is similar to what you'd get from
stepping barefoot onto a marble floor.
Plastic pearls, on the other
hand, will be about room temperature and will warm up more quickly.
Note: Good-quality fake glass
pearls may still give the "cool" sensation. Verify your results with
other tests if this is the first one you've attempted.
Step 5
Feel the weight of the pearl
in your hand. Carefully bounce one or two pearls in your hand to get an idea of
how much they weigh. Most real pearls feel somewhat heavy for their size. On
the other hand, fakes (especially plastic pearls) will have a light,
insubstantial feel.
For obvious reasons, this
test isn't perfect — judging the weight of a few small pearls can be tricky.
For best results, you may want to compare your pearls with a set you know are
real or fake. Always verify with another test no matter how sure you are of a
pearl's weight.
Method 2 of 4: Visual Tests
Step 6
Look for minor imperfections.
As noted above, real pearls are only rarely "perfect". Usually,
they'll have small blemishes or irregularities in their shape. Their outer
nacre layer may also reflect light differently on different parts of the pearl.
Imitation pearls are almost always "too perfect" — they look perfectly
spherical; they have the same amount of luster on every part of the surface,
and show no indents or imperfections.
While perfectly round real
pearls are rare but possible, a necklace will almost never be made only from
these types of pearls. A necklace made from pearls that all seem to be exactly
the same smooth, round shape is almost certainly a fake.
Step 7
Check for a sharp, healthy
luster. Luster is a way that jewelers describe the type of light reflected from
a precious stone. A pearl's luster is part of what makes it so beautiful.
Good-quality pearls should have a bright, clear luster that makes them shine
when light hits them. If you look closely, you should be able to see your own
reflection on the pearl's surface.
One problem with this test is
that low-quality real pearls (which generally have a dull, "chalky"
luster) can look similar to fake pearls. Check your results with a few of the
other tests in this article.
Step 8
Check for an overtone.
Good-quality pearls are often prized for their overtones — the subtle color
that is visible on their outer surface when light hits them. Fake pearls will
usually not have this overtone effect, which is tricky to duplicate. Thus, if
your pearl seems very slightly shaded with color when a light hit is, there is
a good chance its real. Rose and ivory are two of the most desired overtones
for white pearls, though a wide variety of colors are possible, especially for
dark pearls.
Since some real pearls don't
have a visible overtone, not seeing an overtone on your pearl isn't necessarily
a sure sign that it's fake.
Step 9
Look for clues around the
drill hole. Pearls on a strand or necklace will usually have holes drilled in
them for the string to pass through. Examining this hole carefully can help you
tell whether your pearl is real or not. Specific things you'll want to look for
include:
Well-defined edges to the
hole:
Real pearls usually have
drill holes with sharp edges (like a hollow cylinder). Fakes often have rough
or rounded edges. However, old and well-worn real pearls may also have rounded
edges to their holes. Fake pearls may also bow outward at the surface of the
pearl, rather than being perfectly cylindrical.
Chipped paint or coating
around the hole:
As fake pearls rub against
each other with repeated use, their artificial coating can wear away around the
holes. You may be able to see slivers of glass or plastic underneath. This is a
sure sign of a fake.
Step 10
Look in the hole for a line
between the nacre and nucleus. A real pearl almost always has a clear outer
nacre layer, while fake pearls have thin layers of artificial nacre or lack
them entirely. If your pearl has a drill hole, you can check for nacre by
peering in with a magnifying glass. Real pearls will usually (but not always)
have a noticeable line that separates the nacre from the nucleus (the inside
part of the pearl).
Method 3 of 4: Advanced
Tests
Step 11
Check for "scaly"
surface patterning with a microscope. You can use a 30x jeweler's loupe, but
microscopes with 64-power magnification or more work best for this. The
surfaces of real pearls have a maze-like, scaled pattern. This patterning looks
a little like a topographical map. It's this microscopic scaling that gives
real pearls their "gritty" texture.
By contrast, fake pearls will
often have a surface covered with grainy, fairly regular bumps (a little like
the cratered surface of the moon).
Step 12
Compare your pearls to
certified real pearls. All of the tests above are easier if you have some
pearls that you know are real for comparison purposes. Try contacting a jeweler
about the possibility of comparing your pearls to a set of ones that are
certified real. Alternatively, borrow a friend or relative's real pearls to
make your comparisons.
Use common sense about the
sorts of tests you do with the certified real pearls. For example, you won't
want to try the tooth test or the friction test with someone else's precious
stones.
Step 13
Get your pearls appraised by
an expert. If you are having a hard time determining your pearl’s authenticity,
you can always take your pearl to a reputable jeweler or gemologist. These
professionals have the tools, training, and expert eyes to tell whether your
pearl is real (and, if it is real, how high its quality is). However, these
options often don't come cheap — a basic appraisal can easily cost more than
$100.
Step 14
Try ordering an X-radiograph
test. This test, which an expert may do to determine whether your pearls are
real or not, uses an X-ray machine. Real pearls will show up as a semitransparent
grey color on the X-ray. Fakes will be solid white on the negative and solid black
on the positive print.
Step 15
Try ordering a refractometer
test. This advanced test measures how much light passes through the pearl to
determine its authenticity. Pearls usually have a refractometer reading (called
a "refractive index") of between 1.530 and 1.685. The difference
between these two values (0.155) is called the pearl's birefringence, which
affects the way the pearl looks in the light. These qualities tell an expert
that the pearl is most likely a real one.
Method 4 of 4: What to Avoid
Step 16
Beware of using just one test
to verify pearls. This bears repeating: any single one of the tests above can
sometimes produce false results. To be sure of your results, perform many
different tests.
As just one example of how
isolated tests can be misleading, one source found that real pearls that have
been specially polished can feel very smooth in the tooth and friction tests.
Step 17
Avoid the "burn"
test. Some sources may recommend holding pearls in an open flame to determine
whether they are fake or not. According to this rumor, fake pearls will burn or
melt, while real pearls will be unaffected. The truth is more complicated.
While most fake pearls will be damaged by fire, so will some real ones. Real
pearls that have been processed with an artificial outer coating are especially
vulnerable to flame and can suffer from blemishes, deformed drill holes, and
ruined luster after just a few seconds in a flame.
In addition, it's worth
noting that pearls conduct heat well and can become very hot when heated over
an open flame. If you do attempt this test, take all necessary precautions to
avoid bad burns.
Step 18
Don't fall for imitation
pearls sold with exotic names. If a seller is trying to sell you on a pearl's
name rather than its physical qualities, you may be getting ripped off. For
example, "Mallorca" (or "Majorca") pearls, which are named
after the exotic Mediterranean island
of Mallorca but are
entirely man-made, are sometimes sold to unsuspecting costumers.
Step 19
Don't ignore common sense
instincts about a pearl's price. The price of a real pearl will vary greatly
based on its size, shape, overtone, and other features. However, they will
never be outright cheap. For instance, a necklace made from freshwater pearls
(the cheapest variety of real pearls) can easily retail for several hundred
dollars. If a seller is giving you a deal on a set of real pearls that seems
too good to be true, it probably is.
No comments:
Post a Comment