Pearls: real of fake?
Before the 1920s all pearls spontaneously ocurred in the wild, typically when a grain of sand, shell, bone, coral or other irritant accidentally entered a shell of an oyster, clam or mussel. The mollusk begins to produce secretions of natural proteins and minerals called nacre. Over time, the nacre layers build up concentrically around the irritant, eventually forming what we know of as a gleaming, gorgeous pearl! Historically, natural were harvested in the Persian Gulf by divers but the practice has stopped in the 1930s with the discovery of oil in the area.
The variety of mollusks that produce pearls live in fresh water (rivers, lakes and ponds) or saltwater (sea or salt marshes). Cultured pearls began by grafting a tiny mother of pearl core or mantle tissue in the shell of pearl-producing mussel to start the process of forming a pearl. The pearl is generated around the mantle tissue, which eventually deteriorates, leaving a pearl made up entirely of crystalline nacre. Although it did not start naturally, cultured pearls form through the same coating process as natural ones, the mussel depositing layer upon layer of nacre.
By contrast, imitation, artificial, faux, fake, simulated, synthetic or manmade pearls are manufactured with the use of glass, plastic or resin and not inside a livings organism.
Here are 10 ways you can tell a real pearl from a fake:
Price: Price is typically a first indicator. High quality pearls are considered gemstones, and as precious gems, they will cost considerably more than those made of synthetic materials.
Setting: In a finished necklace or bracelet, real pearls are more likely than faux to have knots between each pearl. Pearls should not bunch or twist, knots should be shaped uniformly and pushed snugly against both sides of every pearl and the silk cord should match the pearl color as closely as possible.
The tooth or rubbing test: In this famous test, rub the surface of the pearl over a tooth. If the pearl is real, the layers of nacre should feel gritty, almost like fine sand. Faux ones feel smooth, since the layers are applied on a perfectly smooth bead. An alternative way is to rub pearls against each other instead of your tooth. Imitation pearls glide across each other but cultured pearls feel gritty because of the layers of nacre However, be mindful that when genuine pearls could also be dyed or have a protective coating applied to them, making it more difficult to tell the real and the fake apart.
Light: Hold the pearls out into the sun or under very bright light. Genuine pearls will likely not be a perfect match in iridescence and colour, and you will notice slight variation in shapes or overtones. If the pearls are perfectly matched they are most probably fake.
Surface: Use a magnifying glass to inspect the pearl and look for natural irregularities. When it comes to appearance, man-made faux pearls are more susceptible to chipping, peeling and flaking. Some fakes are made to look irregular, and glass pearls often have flattened ends or slightly oval shapes.
Shape: Real pearls vary in size and shape, but tend not to be perfectly round, so a perfect sphere should be suspect. Highest end genuine pearls may be round, but there will be other clues to help make a determination.
Weight: Density is the mass of an object as a function of its volume. Real pearls are heavier for their size than plastic, resin, or hollow glass beads. Good quality glass fakes may have a similar density as real pearls, and in this case it may be difficult to tell real from faux on the basis of this characteristic alone.
Warmth: Genuine pearls tend to warm to the skin much faster than glass ones. By contrast, resin and plastic tend to feel somewhat warm upon first contact.
Drill holes: Drill holes of real pearls tend to be as small as possible (with few exceptions), since the weight of a pearl effects its price (more hole means less weight and lower value). Real pearls tend to be drilled from both sides to meet in the center. Fake pearls often have larger, possibly straighter holes than real pearls, but some fakes are made to have smaller holes, so they can be knotted like their genuine counterparts. Inexpensive fakes may have holes of variable sizes on a single strand or be chipped around the hole. The “nacre” of fake pearls is more likely to flake away near the drill hole than on a cultured pearl. The holes of fake pearls often form a shallow bowl shape, while the holes of real pearls are more likely to be flat. Examining the hole is also a good way to detect signing of dyeing.
X-ray test: Certified gemologists can perform X-ray tests to identify whether the pearl is natural or cultured. The x-ray will show the variations of density inside the pearl, the size of the core, the size of the layers of nacre and any drill holes.