Where Do Pearls Come From?

open empty oyster shell with a polished pearl inside

While most precious gems are formed in the Earth, pearls are the only “gemstone” created inside of a living creature. Mollusks including oysters, mussels and clams are the bivalves responsible for creating pearls. These beautiful round jewels are the result of a biological process within the oyster as it protects itself from foreign substances. Let’s learn more about how they do it and why pearl jewelry is so unique! 

Where Do Pearls Come From? 

Although clams and mussels can produce pearls, it’s rare and they aren’t made of nacre. Most pearls are created by oysters and can be made in freshwater or saltwater environments. These mollusks have rough and rocklike exterior shells, but like every bivalve they have soft, fragile bodies on the inside. As oysters grow an internal organ called the mantle uses minerals from the oyster’s food to produce a substance called nacre which is the material that forms its shell. 

Pearls are most often made by marine oysters as a natural defense against an irritant such as a parasite or grain of sand entering their shell; it’s similar to getting a splinter in your finger. The irritating particle functions as the nucleus of the future pearl. To prevent damage to their fragile body, the oyster slowly secretes layers of nacre, also known as mother-of-pearl, which encases the irritant and protects the mollusk from it. 

Nacre is a composite made mostly of aragonite that is strong and iridescent. The unique luster or glow of pearls comes from this material. The oyster coats the irritant with thousands upon thousands of layers of nacre, and over time a pearl begins to form. How long it takes for a pearl to form is dependent on the growth rate of the nacre, but most pearls typically take anywhere between two to four years to fully develop. 

How is Pearl Jewelry Made?

Depending on the size and shape of the irritant the resulting pearl can take on a variety of sizes and shapes. The most sought after pearls are round; less-desirable shaped ones are called baroque pearls. The color can also vary based on the part of the ocean or body of water where the mollusk lives. The ideal pearl is perfectly round and luminous but often they come in unusual shapes and different colors including gray, red, blue, green and even black.

Because it takes so long for a pearl to form they can be difficult to find in the wild. Most pearls today are farmed. Cultured pearls are created the same way as naturally occurring ones. Farmers intentionally insert an irritant into the oyster then put it back in the water to grow a pearl over a course of two to five years. Cultured and natural pearls are considered to be of equal quality although cultured ones are often less expensive because they’re not as rare. 

Before pearls are sold to jewelers they have to be prepared which includes: finishing, sorting, drilling, matching, and threading. After being cleaned pearls are sorted by size, shape and color. Pearls used for bracelets and necklaces are drilled all the way through, while pearls for earrings are half drilled. Matching is a time-consuming process where an expert looks through thousands of pearls to put together matching sets. 

Whether you’re shopping for a June birthday, a 30th anniversary gift or timeless jewelry, pearls are perfect for girls and women of all ages and they’re complimentary for almost any occasion. Give us a call at 303-385-8449 or click here to schedule a jewelry appointment