Pearls come in many shapes and sizes whether they are real or not, and it’s not always easy to tell the difference between those that are genuine and those that are imitations. Even amongst genuine pearls there are many different classes of both natural and cultured varieties, all with their own different properties and all valued very differently as pearl jewellery. Before buying any pearls it’s important that you know what you’re getting, so here are a few ways to help differentiate between a genuine pearl and a fake:

The Tooth Test
It’s said that if you rub a pearl against the biting edge of your front teeth, the texture of the surface will tell you whether or not it is genuine. Real pearls normally have a more rough, irregular texture whereas fakes are glassy and perfectly smooth. This isn’t really the most reliable method of testing, as fakes are often made to appear completely genuine and cultured pearls in particular can often be very smooth, especially if they are dyed.

The Sun Test
A slightly more reliable method is to take the pearls out in the sun and take a close look at the appearance of the lustre, or shine, that you see on the surface. Apart from extremely unusual and rare specimens, genuine pearls won’t be perfectly matched under the sun and have clear differences in shine, iridescence and colour.

Surface Magnification
Don’t underestimate the power of a magnifying glass – a closeup look at the pearl earrings, necklace or brooch can tell you a lot, and is one of the most effective ways of distinguishing between genuine and fake pearls. The surface of a real pearl is crossed with hundreds of tiny almost invisible crooked lines, giving them an almost scaly look when placed under the microscope. Whilst there you could also take a look at the small drill holes at either end of the pearl, which in a real pearl will be as tiny as they can be because larger holes devalue the gem. Real pearls usually have holes drilled from either end, making the passage narrower at the centre of the pearl.

Shape
One of the most obvious ways to identify real pearl sets is to look closely at the shape of each pearl and whether or not they are close to being identical – real pearls are hardly ever perfectly round, and it is almost unheard of to find a whole string of pearls of exactly the same size, shape and weight. Real pearls that are regular in this way are extremely expensive, and if not they are probably fake.

X-Ray
The best way to be absolutely positive of a pearl’s authenticiety is to have it verified and certified by a qualified gemologist. For a fee they will be able to x-ray the pearls, showing any variations in density and identifying the nucleus to determine how the pearl was originally formed. To be worth paying the price you need to first be fairly sure that the pearl is genuine, but many imitation pearls look very real and without damaging the pearl it really is the only way to be completely sure.