How To Determine Real Pearls
Here are a few quick tests you can easily perform to determine if pearls are real or fake

How can you tell if pearls were produced by an oyster or by a machine in a factory? This is very important to know if you're either buying that perfect pearl jewelry anniversary gift or want to be known as a reputable fine jewelry dealer. Though most any knowledgable jeweler can help you with this question, there are simple steps most anyone can take to see if a pearl is real or fake.
- Touch Test - An old wives' tale says that if you hold real pearls in your hand, they will be cool to the touch for several seconds before warming up. Genuine pearls tend to warm with contact to the skin much faster than resin and plastic pearls, which are often warm on first contact. However, glass pearls take longer to warm in your hand than real pearls. Therefore, this is not a sure-fire method for checking authenticity.
- The Tooth Test - Rub the pearls lightly along the biting edge of your upper front teeth. If they feel slightly rough, sandy or gritty, it's likely they are cultured or natural pearls because of the layers of nacre that have formed over time. If they feel smooth or glassy, they are probably imitations.
- Sunlight Test - Hold the pearls up to the sunlight or very bright indoor lighting. You can check for variations in the pearl's color and tone. If it's perfect in its color and tone, it's very likely fake.
- Magnifying Glass Test - Look at the pearls through an ordinary magnifying glass. You should be able to see the ridges and irregularities of a real pearl, or the grainy smoothness of a fake.
- Weight Test - Real ones are usually heavier than fakes.
- Drill Hole Test - Real pearls are drilled as small as possible to maintain their value, so fakes will often have larger holes. Also, the pearl surface, or nacre, will often flake off around the holes of fakes.
- Pearl Shape Test - Real pearls are a product of nature and, therefore, produced with some degree of irregularity. If it's a perfect sphere, it's likely a fake. Near perfectly round pearls are worth a substanial amount of money.