When you hear the word "pearl," you probably think of a shimmering white orb. But what do you picture when you hear "freshwater pearl" or "baroque pearl"? If you aren't an avid pearl lover, you might have some trouble distinguishing between the many types of pearls out there. In this article, we explain some of the most common terms you'll see when shopping for pearl jewelry, so you can be more confident in your purchase.
More often than not, people assume that the term “cultured” is synonymous with “imitation”, or otherwise implies that the pearl is not a genuine one. In reality, a cultured pearl is no less genuine than one occurring in nature. The only differences between the two are rarity, and the fact that human intervention began the process of creating the cultured pearl. Other than that, the rest is all taken care of by the mollusks in their natural and normal biological processes.
To understand what makes a pearl “cultured”, it's helpful to know the basics of how a pearl is formed naturally. When an irritant, such as a parasite, enters the mollusk, a fluid is secreted as a defense mechanism. This fluid coats the irritant, creating a layer called nacre. Each layer of nacre builds up to form the pearl. In the instance of cultured pearls, the irritant is inserted deliberately by a human (a process called nucleation), and is a piece of mother of pearl shell or bead, rather than a parasite.
Cultured pearls are popular for use in jewelry because they are formed in a much more controlled environment, and therefore are easier to match for use in earrings or beaded necklaces. It is more difficult to match natural pearls to each other, and they are rarer due to past harvesting practices, which is why they tend to be more expensive.
From left to right, this photo illustrates the differences between different types of pearls, with an Art Nouveau necklace with natural river pearls, a Victorian seed pearl pendant, and a cultured saltwater pearl necklace.
Freshwater pearls are any pearls that were formed in rivers, lakes, and ponds. Freshwater pearls have been found in almost every country in the world, but are primarily sourced from China. Most freshwater pearls are cultured.
Saltwater pearls, as you might imagine, are pearls formed in saltwater mollusks. Usually these pearls are referred to by specific names, rather than under the broad classification of “saltwater”. These pearls include Akoya (Japan and China), South Sea (Australia, Indonesia, and the Philippines), and Tahitian (French Polynesia). Akoya pearls are perhaps the most famous kind of saltwater pearl, being the more traditional white, round pearl. Each type of pearl has its own unique characteristics that give it value.
There are a few differences between saltwater and freshwater pearls that affect their appearance. Freshwater pearls have a thicker nacre than saltwater pearls, and therefore may have more depth of shimmer to them. However, this thicker nacre also makes them less lustrous or shiny than saltwater pearls. You will also often find freshwater pearls that are more oblong and less perfectly round, and available in a variety of pastel colors.
It is difficult to rely on these characteristics nowadays to distinguish freshwater and saltwater pearls, because advances in culturing have allowed both types of pearls to be comparable in luster and quality. Generally speaking, price can help you distinguish between the two, as freshwater cultured pearls are usually more affordable than saltwater cultured pearls.
As the name implies, mother of pearl is a kind of parent to the pearl. It is the inside part of the mollusk shell that has that iridescent luster we associate with pearls. Like pearls, mother of pearl is formed by layers of nacre secreted by the mollusk. Instead of forming around an irritant, the nacre forms on the inside of the shell. Mother of pearl is an important component in jewelry making in its own right, and can be carved, threaded into beads, or inlayed into fine metals.
Baroque pearls have a non-symmetrical shape that greatly differs from the traditional round or oblong pearl forms. This French term translates to “irregular shape”, and is also applied to the 17th Century art movement that featured dramatic and bold compositions. Baroque pearls were prized by jewelers during the Renaissance, and continue to be used creatively today.
This beaded necklace makes good use of baroque pearls to create an elegant design.
A mabe pearl is a half-pearl, and is used often in jewelry for its ability to lay flat. Mabe pearls are formed by inserting a dome shaped nucleus into the mollusk with the flat side against the shell. Mabe pearls are generally large and used in statement jewelry.
"Blister" is a term sometimes used interchangeably with “mabe,” however traditionally it was used to only refer to naturally occurring pearls that form inside a coating of mud, water, and mother of pearl. You will also see “blister pearl” referring to a bump formed on the inside of a mollusk shell.
Mabe pearls, like the one in this vintage cocktail ring, have a flat back that allows them to sit flush in a jewelry setting.
River pearls are a highly collectable type of freshwater pearl and typically are elongated in shape. Natural river pearls can have a beautiful petal-like shape and are quite valuable. River pearls are usually formed inside of various species of mussels.
This Art Nouveau era brooch uses natural river pearls that mimic the floral motifs of the piece.
A seed pearl is so named because of its size – usually less than 2 millimeters in diameter. These are traditionally natural pearls and can vary quite a bit in color, from milky white to an elegant dove gray. Their imperfect nature is part of their charm, making each piece they adorn a unique treasure. Seed pearls were popular in Victorian and Art Nouveau jewelry.
A selection of Victorian jewelry set with beautiful seed pearls.
As you can see, pearls come in many beautiful forms. It is difficult to compare different types of pearls to one another, but overall you should look for a good luster, shape, color, and shimmer (quality of the nacre). When shopping for pearl jewelry, look at how well the pearls were incorporated into the overall design. If you are buying a classic strand of pearls, the pearls should be well-matched in color and size. Pearl jewelry can range from ornate and elegant, to minimalist and chic, making it the perfect gemstone to match your individual style.