Pearls: How to Spot the Real Deal

Nov. 28, 2001 -- Diamonds may be a girl's best friend, but thousands of women still lust for the timeless elegance and glamour of pearls.

But can you tell a top-of-the-line strand from a second-rate — or a just plain fake — one? Experts say most of us probably can't.

"There is no way a lay person can tell," says Cos Altobelli, an expert gemologist and appraisals chairman for the American Gem Society. "You have to depend on someone who sounds knowledgeable."

Pearls are the only precious gems that are produced by a living creature. Most pearls on the market today are cultured, which means they are made at an oyster farm by inserting a small piece of shell into an oyster. The oyster then secretes a silky coating around the irritant — layer by layer — until a pearl is formed. The quality of cultured pearls varies widely.

What You Should Know

So how do you know the truly valuable from the second-rate? Here are some tips:

•Color: Though white is often preferred by people with fair skin, the most valuable pearls are white with a rose overtone. Some complexions may look better with cream-color pearls, which are also less expensive than rose ones.

•Surface thickness: Also important is the thickness of the nacre, the substance that is deposited on the bead when it is placed in an oyster. A thick nacre is best. To test it, Altobelli suggests holding a strand of pearls next to a bright light and rolling the pearls. "If they have a thin nacre, the pearls will blink at you," he says. "This has two resulting effects: poor luster, and if you wore them every day for a fair length of time, it would wear through the nacre."

•Luster: "It is what gives a pearl a striking appearance rather than being pale or uninteresting," says Altobelli. The thicker the nacre, he explains, the better the luster.

•Shape: Perfectly round pearls are the most coveted. Baroque or semi-baroque shaped pearls, meaning slightly out of round to substantially out of round, can be relatively inexpensive. If you roll pearls on a flat surface, you can see if they are slightly elliptical or not quite perfectly round.

•Size: What carats are to diamonds, millimeters are to pearls. "Like any gem, size is going to have a major role in what the price of the pearl is going to be," says Altobelli. But, he notes, you should also take into account the size of the person wearing them, including height and neckline, because the pearls should be proportionate.

•Blemishes: A pearl is not considered high quality if it has blemishes, or as expert gemologist describes it, "bump, bump, bump, bump … like a pepperoni pizza."

•The Tooth Test: To find out if a pearl is real, lightly rub it against the front of your tooth — not against the edge, which can scratch the pearl. If natural or cultured, rather than simulated, the pearl should feel gritty.

•The Grading Game: There is no industry-wide grading system, so jewelers often make up their own. They also sometimes borrow the grading system used by Mikimoto, the most recognized name in pearls. Though other vendors may say their pearls are Triple-A, which is Mikimoto's highest rating, their versions may not be equivalent.

•Match: Pearls on a strand should all match in terms of color, luster and roundness.

•Drill Holes: Though this is a less important factor than the others, the drill holes should be properly centered. "If the drill is off center," says Altobelli, "the pearls will roll differently on the strand."

•Other tips: Find a reputable dealer, get all the claims about what you buy in writing, and get a money-back guarantee in case your pearls turn out to be lemons.

This story originally aired on Primetime on Nov. 1, 2001.