Determining Authenticity in Gemstones and Pearls

Image of an emerald laid within set diamond jewelry necklace

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When buying gemstones and pearls, it is important to know if they are genuine or an imitation.


Very similar to how diamonds are priced, colored gemstones with better clarity will cost more per carat. Having a gemstone with a better cut is often worth a bit more, and the bigger the stone, generally, the more it is worth per carat. Within each variety of gemstone, prices are calculated according to the four C’s: carat, color, cut, and clarity, with color being by far the most determining factor.

In general, there’re 7 Pearl Value factors that affect the pearl value: shape, size, color, luster, surface quality, nacre quality, and matching, similar to the 4Cs for colored gemstones and diamonds listed above.

Gemstones and pearls can be expensive; you wouldn’t want to end up paying for a genuine piece only to get the quality of an imitation. In most cases, imitations are synthetic, which means they were created in a laboratory to be a substitute for a real gemstone or pearl. This is one reason why it can be hard to distinguish them; synthetics are made to look just like the real ones.

While at-home methods can be effective in determining whether your gemstone or pearls are real, the most reliable way is to take the stone to your local jeweler for evaluation.

Do you want to determine the worth of your colored gemstone? Call us today for a free consultation.

However, if you still want to test at home and want to go a little further than just appearance and weight, here are some common tests for gemstones and pearls you can do to make sure you are getting an authentic item.

Looking for a guide on how to determine if your gold jewelry is real? Read more here.


One thing to remember is that real gemstones and pearls are natural and because of this, they are going to have flaws. Real items have been worn down through factors like time and the environment and often because of this, fake gemstones will sparkle and shine more than natural, authentic ones. For pearls, when examined closely or under magnification, you’ll notice tiny irregularities and ridges on each pearl’s surface.

Another thing to consider during the first evaluation is how much the item in question weighs. Normally, synthetic stones are going to be denser than real stones and therefore should be heavier. The difference should be noticeable by just holding the stone in your hand. Real pearls, on the other hand, will weigh more than their counterfeits.


One stone that is commonly replicated is the ruby. Real rubies glow with a deep, vivid red; fake gems are often dull. If the gem is more of a dark red, then it may be garnet instead of a ruby.

Another way to test a ruby is through a scratch method. Real rubies are extremely hard stones and will not scratch under most conditions. Rub a fingernail or a coin on the surface of the stone and see if you can scratch it. If the ruby shows a scratch, then there’s a good chance that it is not genuine. You can also gently scratch the stone against a hard surface like a porcelain tile or a piece of glass. If the stone is genuine, it will not leave a red mark on the surface where you scratched it, if it does it could be a sign that the gem is artificially colored.


Sapphires are typically blue but can also be red, yellow, orange, green, or other colors in between. Fake sapphires tend to be brighter than natural ones and shine more.

Sapphires come in right behind diamonds in terms of gemstone hardness. So, it can be easy to use the same type of tests for sapphires that you would use on rubies. You can also look for scratches on the sapphire.

Another common sign of an inauthentic sapphire are air bubbles in the stone; Since they are often made of glass, tiny air bubbles remain in them after they form. If you see any bubbles inside of the sapphire, then it is not real.

You can also perform a breath test on sapphires by counting how long it takes for the fog to clear. Natural gems should clear up in just one or two seconds, but lab-created sapphires may take five seconds or more to clear up.

Need more help determining if your rubies or sapphires are real? Call us today for a free consultation.


It can be difficult to determine the authenticity of Emeralds. Many “emeralds” are actually other green gems, green glass, or imitations built from several materials. 

With emeralds, one common way to look for a fake is to check for a “sparkling” effect. Real emeralds produce little or no “fire,” colorful flashes that appear under a light. If your gem produces a rainbow of flashes, it is not an emerald.

You can look at the color to help you determine whether an emerald is fake. The mineral beryl is only called emerald if it is dark green or blue-green. Yellow-green beryl is called heliodor, and light green beryl is just called green beryl. Most emeralds will be in the range of these mixes of colors and not pure green.

This is very different from fake emeralds which are produced to have a brilliantly deep green color. If the stone in question is more of a deep bright green, then it could have been created in a laboratory.

Need more help determining if your emeralds are real? Call us today for a free consultation.


You may have heard of the classically trusted method of determining whether a pearl is real – by putting the pearl in your mouth and scraping it against your teeth. Both natural and cultured pearls have a textured surface due to their layered structure. When you rub the pearls lightly against each other or on your front teeth, they feel a little gritty. Fake or imitation pearls, however, often feel smooth or glassy.

But what if you don’t know where the pearl has been and don’t want to put it in your mouth?  Running your fingernail across the pearl should give you the same results.

You can also check for any drill holes in the pearl- drill holes in genuine pearls are usually very small in comparison to those in imitation pearls. When magnified, the area around the drill holes of fake pearls will often have a very thin coating which looks like shiny paint. Good indicators fake pearls are flakes or chipped pieces of this coating around the drill holes.

Another way to tell if a pearl is genuine is to test the temperature of the pearl. After letting it sit away from the skin’s temperature for a while (store in a bag or on another surface), hold the pearls in your hand and see how they feel against your skin. Real pearls should feel cooler than your skin for a few seconds before they react to your body heat, like touching marble.


Many of these methods for testing colored gemstones and pearls at home have been used for decades and can often be a good indicator of whether the piece in question is authentic.

Ultimately, the safest way to be sure is to have a professional jeweler look at the gem. They can assist you in determining authenticity before making a large purchase. They can also tell you whether your stone is real without any damage to the piece.

Do you want to determine the worth of your colored gemstone? Call us today for a free consultation.

Photo by engin akyurt on Unsplash

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