First of all, you should know that real pearls can be either freshwater or saltwater (sea) pearls. The difference is in how they’re grown, their shape, and of course their price. Today virtually all real pearls are cultured artificially by seeding but it still takes several years before they are formed.
Testing to see if pearls are real
An experienced jeweler can tell at first glance whether a pearl is real. If you want to try it, take the pearl in your hand and have a good look at it. You’ll need good light and maybe even a magnifying glass. Here’s what you’re looking for:
Slight imperfections – Nature is perfectly imperfect, and that’s especially true of pearls! Real pearls have slight imperfections – an uneven surface, variations in luster, and tiny pits and grooves. A real pearl is actually less perfect than its imitation. In a necklace of real freshwater or saltwater pearls each pearl is different, whereas every pearl on a string of fakes is exactly the same.
Shape – Freshwater pearls come in all shapes and sizes, from round and oval to oddly shaped baroque pearls. Saltwater pearls tend to be round, but never perfectly; each pearl in a string of pearls is unique because each formed in a different mollusk (actually, a single sea mollusk can form two pearls and a freshwater mollusk as many as 32 pearls. It still holds that every pearl is different, even if they come from the same mollusk). The more uniform real pearls are, the more expensive they become, so if all of the pearls in a necklace are equally lovely and round, and the price is suspiciously low, you can bet you’re looking at fake pearls.
Weight – Real pearls are fairly heavy. A plastic imitation will seem light in comparison, and you’ll know the difference immediately. Manufacturers of false pearls are clever, however, and some make pearls from denser materials, like glass, so the result may feel about the same as a real pearl.
Overtone – Like their shape, the color of fake pearls is also perfectly uniform. Real pearls, on the other hand, may combine various colors and, what’s more, have colored overtones that vary from pearl to pearl. Be cautious when you see oddly colored pearls – natural tones are usually white, pink, peach. Unexpected colors can indicate that you’re either looking at a fake or a real pearl that has been dyed (also a possibility).
Drill hole – If you’ve got sharp eyes, or you have a magnifying glass on hand, take a good look at the area around the drill hole where the string goes through. A real pearl will have a small hole with sharp, clear edges. Imitations tend to have a larger hole and sometimes there may even be signs of peeling or traces of the coating process.
Temperature – Real pearls feel cool to the touch (unless you’ve just been wearing them). They warm up as you hold them.
Luster – Imitation pearls have a uniform, glassy luster. Real pearls, in contrast, each reflect light slightly differently because of tiny surface imperfections and their luster is deeper, giving the impression that it comes from the very core of the pearl. Imitation pearls will only have a shiny surface.
Size – Since pearls have a limited space to grow, they can only get so big. A large pearl would be 10 mm in diameter (3/8"). If you come up against an unusually large one, say 14 mm (1/2") and more, beware. A pearl that size would be very rare and extremely expensive.
Price – The cost of pearls is affected by a variety of factors. In general, the larger, brighter, and rounder a pearl is, the higher its price will be. So, the more perfect a real pearl is, the more expensive, but also the harder they are to tell from imitations. A string of small, irregular freshwater pearls may cost ten or twenty dollars, while a necklace of large, round freshwater pearls can bring a few hundred. Sea pearls are more expensive still, a similar string asking as much as a thousand dollars or more.
Aside from examining your pearls visually, you might want to try some of the following tests:
The most common test, rubbing will give away most synthetic pearls for what they are. The trick is that when you rub real pearls together, there is some friction and a tiny amount of nacre will rub off, leaving a fine powder. If you rub together two fake pearls, they’ll just slide against each other smoothly. The difference is pretty obvious when you rub a pearl against your teeth. You might also try carefully scraping the surface of the pearl with a knife – real pearls will lose a dusting of nacre but will remain as if untouched after you’ve run a finger over the area, whereas fake pearls will show a scratch.
Have you ever found yourself at a bustling Asian bazaar, pressed by an insistent pearl merchant waving pearls and a lighter in front of you? If you expose a real pearl to an open flame for a short time, nothing will happen to it. Some synthetic pearls, however, will be scorched or lose their shine. The method is not foolproof, however. There are many imitations (such as glass) that pass this test with flying colors. Besides, exposing real pearls to an open fire is not especially good for them.
If your pearl is real, an acetone solution should do it no harm. In contrast, acetone dissolves the coating on synthetic pearls, leaving marks or causing the pearl to lose its luster entirely.
A word to the wise – never rely on a single test for telling if a pearl is real. Some imitations are so faithful that they can pass many of these tests without a problem.
Types of fake pearls
If you want to tell the difference between a real pearl and an imitation, it’s good to know what kinds of fakes are out there.
Plastic pearls – Plastic pearls are the cheapest imitation and are easy for most people to recognize. They’re light and cheap looking, with messy drill holes where the coating is visible. The really dirt-cheap ones may even be molded to the string.
Glass pearls – Probably the most common fakes, glass pearls can be made two ways. Either a glass bead is given a layer of pearly coating or else a hollow glass bead is filled with wax. In the latter case, the resulting fake pearl is very fragile and easy to break (see photo). Glass pearls are heavier than plastic pearls, but they still have a uniform surface and luster, so on closer inspection they are easy to recognize.
Shell pearls – You might say that a shell pearl is to a real pearl as cubic zirconia is to a real diamond. Shell pearls are synthetically produced real pearls – the core of the pearl is sculpted from the mollusk shell, so it’s actually the same material that a real pearl is made of. Cheaper versions have a glass core coated in powdered nacre from real pearl mollusks. For shell pearls the rubbing test won’t give them away, so you have to rely on visual examination, which takes experience. Shell pearls tend to be large and
Majorica – The Spanish company Majorica is a leading manufacturer of very faithful imitation pearls. Their manufacturing process is a closely guarded secret, but we know that the core of the pearl is glass and the surface is a sophisticated mix very like nacre. The process is so perfectly done that it’s extremely difficult to tell the difference from real pearls. Each string is made up of pearls that are all slightly different, with ridges and slight imperfections on the surface. They’re not particularly cheap either, with a string of pearls priced at around a hundred dollars and up.
Majorica pearls – A perfect imitation of baroque freshwater pearls. Each pearl is different and irregular, but all have a suspiciously high luster
Browse our real freshwater pearls – for yourself or for someone special.