Real Pearls VS. Faux Pearls

(Photograph by Josh Humbert)
What Is a Pearl?
Pearls are formed when a round nucleus is inserted into an oyster, which then is covered by several layers of nacre. Now what is nacre? I thought it was a funny word too when I first heard it. Nacre, also known as mother-of-pearl, is an organic substance that is secreted by the oyster that gives the iridescent look to a pearl. Each layer of nacre is unique, resulting in every pearl being different from the next. Now keep in mind, almost all real pearls today are cultured. Finding a 100% natural pearl without human influence is extremely rare and those that have been found, are in museums.
How To Identify Real Pearls Vs. Faux Pearls
Being able to tell real pearls from faux pearls is going to potentially save you from heart break and wasted money. Faux pearls are beads made from plastic, glass, or crushed up shells made to look like real pearls. Next time you're shopping for pearls, make sure to keep these tips in mind.
The first thing you're going to notice is real pearls are cold when you first touch them. Because faux pearls are usually made out of plastic, they are going to be room temperature to the touch. 
If an entire string of pearls are the exact shape, size, and seem to have zero imperfections like real pearls, they are most likely fake. With the layers of nacre, there's going to be some imperfections and every pearl is different.
Another important thing to watch out for is the color. Real pearls have a luster to them that shows depth and different hues of pink, green, or blue. Faux pearls have usually one uniform color to them, lacking depth and luster.
The final tip that is usually the easiest to determine real pearls from faux pearls is the weight and surface feel. Real pearls are dense, as well as heavier than faux pearls. Lastly, if you rub two real pearls together, it'll feel almost grainy or like sand, while rubbing two faux pearls feels smooth. Until your eye has been trained to determine the two apart, rubbing the pearls together is always a safe trick to rely on. I hope these tips were helpful!