How Do Freshwater Pearls Get Their Color? 6 Interesting Facts

When someone mentions pearls, the first thing that probably comes to mind is a perfectly spherical white or slightly off-white stone. While this variety is one of the most prized, however, it certainly isn’t the only one out there. Freshwater pearls come in white, black and nearly every color in between. Many of these colors form naturally, but some hues are created by artificial means.

Freshwater Pearl Color Beads

If you are a jewelry designer who is interested in using colorful freshwater pearls in your creations, keep scrolling to discover a few interesting facts about how freshwater pearls get their color.


The Color of the Mollusk’s Lip Often Plays a Role in the Color of the Resulting Pearl

Cultured freshwater pearls are created by implanting an irritant inside of a mollusk that produces pearls. The type of mollusk used during this process often has an impact on the color of the resulting pearl. The lip, or the outer part of the shell, influences the color of the pearl that will form inside the mollusk.

For example, Tahitian pearls get their dark coloration from the Tahitian pearl oyster, which has a black lip. The distinctive light to dark gray Tahitian pearls typically form in only this type of oyster. And the black-lipped Tahitian pearl oyster very rarely produce pearls of other colors.


The Iridescence Comes from Nacre

River Pearls

While it isn’t exactly a “color,” the iridescence is one of the most striking features of any pearl. It is a natural phenomenon that makes it look like the surface of a pearl changes color when viewed from different angles or under different types of light. This same phenomenon also occurs on things like soap bubbles, butterfly wings and the wings of certain birds.

In pearls, the layers of nacre that build up around an irritant inside of a mollusk create iridescence. Nacre is a transparent, crystal-like substance, but as the layers build up, it creates a brilliant play of color in the resulting pearl. The thicker the nacre, the more richly colored the resulting gem will be.


The Substance That Holds the Layers of a Pearl Together Can Impact Color

The layers of nacre that form during the creation of a pearl are held together by a substance known as conchiolin, which acts as a sort of organic glue. The conchiolin may be naturally tinted with shades of brown, gray, black, red or other colors. When this pigment is present, it is visible through the crystalline layers of the pearl to create the appearance of various colors at the surface of the pearl.


Overtones Come from Aragonite Platelets

Microscopically thin, semi-transparent crystals known as aragonite platelets are also present in the layers that make up pearls. They are hexagonal in shape, and they make up the pearl’s prismatic layers. When white light penetrates a pearl, the beam of light is refracted back toward the viewer in its entire spectrum. This allows one to see shades of red, orange, yellow, green, blue, indigo and violet in the pearl. The aragonite platelets in the pearl are responsible for determining the exact color(s) you see.


Some Pearls Are Dyed

Multiple strands of colored pearls

While pearls form in all sorts of beautiful colors and shades all on their own, certain colors can only be achieved through a dyeing process. If you are searching for vibrant blue, dark green or cranberry red freshwater pearls, it’s likely that the ones you find will have been commercially dyed.

Typically, an organic dye is used to color freshwater pearls. Sometimes, this is done to replicate the colors of saltwater pearls. In other cases, however, this dyeing process is used simply to create vibrant colors that do not form naturally. As long as you purchase high-quality freshwater pearls that have been dyed with care, this type of treatment does not detract from the value of the stones.


The Color of Freshwater Pearls May or May Not Impact Their Value

In some cases, the color of a freshwater pearl affects its value. In others, it doesn’t. Generally speaking, though, pearls that are mostly uniform in color tend to be more valuable than those that are not. Because it is possible to achieve virtually any color in a cultured pearl, certain colors (like black) are not as rare or valuable as they once were.



Adding colorful freshwater pearls to your collection of jewelry-making supplies is an excellent way to allow yourself to design unique and beautiful creations. Choose whichever colors you like best and enjoy experimenting to create designs you love.