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. [4] X Research source
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.
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.
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.
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. [8] X Research source
It is possible for real pearls to be perfectly round. However, examples of these are very rare and usually fetch a high price. [9] X Research source 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. [10] X Research source
Plastic pearls, on the other hand, will be about room temperature and will warm up more quickly. [12] X Research source 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.
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.
By contrast, fake pearls will often have a surface covered with grainy, fairly regular bumps (a little like the cratered surface of the moon).
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.
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.
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.
As a general rule, you’ll only want to buy pearls from licensed, certified jewelers and pearl retailers. Buying pearls from street vendors or pawnshops can be a risky proposition. See our pearl-buying guide for specific tips.
