Pearls are classified into various categories based on a variety of factors, the most important of which are size, shape, and origin. These criteria will be used to evaluate the various types of pearls in this article.
If you want to learn everything there is to know about these fascinating gemstones; you’ve come to the right place. Make yourself at ease as we take you on a journey through the pearl universe.
What Are Pearls, And How Are They Made?
A pearl is a hard, lustrous, often spherical item formed within the mantle of a living shelled mollusk, most commonly an oyster, but it may also be formed in other related animals such as mussels, clams, or sea snails.
Like a mollusk shell, a pearl is made of calcium carbonate in minute crystalline form that has been accumulated in concentric layers.
The process of pearl formation is a result of the defense mechanism in these animals. Both freshwater and saltwater mollusks produce pearls as a natural defense against an irritant penetrating their shell or causing harm to their sensitive bodies, such as a parasite, bone, or even a grain of sand.
As a result of the irritant’s infiltration, the oyster or mussel gradually secretes layers of aragonite and conchiolin, which make up its shell. This causes the creation of nacre [NAY] + [KUH], sometimes known as “mother-of-pearl,” which encases and protects the mollusk from the irritant.
During the commercial growth of pearls, an irritant is surgically placed into a mollusc to induce the formation of mother-of-pearl or nacre.
Almost any irritant that enters the shell can induce nacre to form naturally, producing some incredibly uncommon and precious pearls.
Types of pearls (origin)
Based on origin, pearls can be classified into two categories. The process of pearl formation may be human-induced or completely natural. Pearls that are formed as a result of the direct activities of humans are known as “cultured pearls,” while those that do not involve any human assistance are called “natural pearls.”
As has been stated earlier, cultured pearls are formed by a human-induced process. Owing to the fact that the process of pearl formation is quite slow, pearl farmers, through a process called “pearl cultivation,” try to induce pearl formation in mollusks. The process involves the surgical insertion of an irritant into a shell bead nucleus inside the soft tissue (mantle) of the mollusk. In response to this irritant’s presence, the mollusk’s defense mechanism deposits layers of nacre on the shell bead nucleus via a natural process, just as it does in natural pearls. The presence of a round shell bead nucleus improves the chances of round pearl production, although this is not always the case. Furthermore, the nacre layer in cultured pearls is often thinner than in natural pearls.
Natural pearls are formed in a process that is quite similar to that of cultured pearls. The only difference is that irritants enter the mollusk’s mantle naturally rather than being implanted surgically. When the irritant enters, the same process of nacre deposition on the irritant that occurs during cultivated pearl creation occurs. Because there is no shell bead nucleus, the amount of nacre deposited during the production of natural pearls is usually greater.
Types of cultured pearls
The vast majority of pearls available today are cultured. Pearl diving is no longer as popular as it once was due to a variety of issues. As a result, any pearl you see today that isn’t an antique is almost certainly a cultured pearl. With this in mind, we will review the various varieties of cultured pearls based on their origin.
Freshwater cultured pearls are pearls that form in freshwater mollusks (mussels). They are the most widely produced and, consequently, the cheapest pearl variety around today. A single freshwater mussel is capable of producing up to 40 pearls per harvest. Due to the large number of pearls forming simultaneously, freshwater pearls come in a wide variety of shapes and colors. Typical sizes found in the market range from 7 mm to 12 mm.
Freshwater pearls are known to come in the wildest of shapes. They are rarely perfectly spherical in shape. A baroque-shaped pearl has uneven symmetry, which is typical of most freshwater pearls. Freshwater pearls can also be found in the following shapes: button, stick, drop, coin, off-round (near-round), and very rarely, spherical.
- Akoya pearls
Akoya pearls are saltwater pearls cultured in the Akoya oyster (Pinctada fucata martensii). They are the least expensive and, thus, the most plentiful of the saltwater pearls. They have the longest cultured history of saltwater pearls, as they were the first pearls to have been cultured by Kokichi Mikimoto, the Japanese entrepreneur credited with creating the first cultured pearl.
Compared to freshwater pearls, Akoya pearls are smaller and rounder. Unless color-treated, Akoya pearls exhibit neutral colors and overtones. Most pearls range in hue from white to gray, with pink, green, or silver overtones. Akoya pearls can occasionally be blue with silver and pink overtones, but these colors are extremely rare. Typical Akoya pearl sizes range from 6.0 mm to 9.5 mm, and round, near-round, teardrop, and baroque are all common shapes.
- Tahitian pearls
Tahitian pearls are not created in Tahiti, as the name implies. Tahiti is the primary island center of French Polynesia, a collection of five island archipelagos known for their Tahitian pearl production. Tahiti is thus primarily a trading post for atolls that generate Tahitian pearls rather than a producer in its own right. Tahitian pearls display an amazing range of colorful overtones. Although traditionally referred to as black in color, pearls don’t come in black unless dyed. The same is true for Tahitian pearls, which are generally described as being black.
Tahitian pearls usually have dark colors: blue, green, purple, brown, etc.
Tahitian pearls are much larger than Akoya pearls. The pearls range in size from medium to enormous. Tahitian pearls are available in sizes ranging from 8 to 18 mm. However, the most common market sizes range from 9 to 15 mm. Being larger in size than Akoya pearls, they offer a wider variety of shapes, including round, semi-round, button, teardrop, pear, oval, baroque, and circle baroque.
- South Sea Pearls
South Sea pearls are grown in saltwater oysters from the South Sea. They are the largest cultured pearls available. South Sea pearls are at the top of the pyramid when it comes to pearls due to a number of factors, such as their large size, rarity, and durability (as a result of their thicker nacre coating).
South Sea pearls range in size from 8.0 mm to 20.0 mm, with an average size falling between 12.0 and 15.0 mm. Sizes larger than 15.0 mm are very rare and expensive.
There are two different types of South Sea oysters (Pinctada maxima), which determine your pearl’s color. Silver-lipped South Sea oysters produce pearls of a white or silver color, while gold-lipped South Sea oysters produce pearls with shades of yellow, gold, cream, champagne, and other warm colors.
South Sea pearls are available in a range of shapes. The rounded one is the most uncommon. It takes about three to five years for this pearl to form, and during that time, various events might influence its formation, changing its intended shape. With that said, here is a list of the various shapes in which South Sea pearls come: round, semi-round, baroque, button, oval, and ringed.
Types of natural pearls
There are two types of natural pearls based on their origin. They are natural saltwater pearls and natural freshwater pearls.
Natural saltwater pearls
Natural saltwater pearls, as the name implies, are pearls that form naturally in saltwater mollusks. These types of pearls are extremely difficult to discover anymore due to a variety of issues, including open-water pearl diving regulations, ocean pollution, natural predators preying on the oysters, and the inherent hazards of pearl diving.
These variables have played a significant role in preventing people from diving for pearls. Furthermore, data show that only one in every 10,000 oysters produces usable pearls. These odds are not appealing and are certainly not worth the risk of pearl diving.
- Size and shape
Natural saltwater pearls have a higher nacre content than cultured pearls and natural freshwater pearls. The high nacre concentration increases the relative durability of natural saltwater pearls. Natural saltwater pearls have frequently set and broken records for pearl size.
Due to their relatively undisturbed growth, these pearls can grow to reach dimensions not seen in cultured pearls. For example, the Puerto pearl grows to a length of 67 cm (26.37 inches) before being harvested and weighs an incredible 34 kg. Natural saltwater pearls almost always come in baroque shapes as they grow wildly; very rarely will you ever find a perfectly spherical natural pearl.
Natural saltwater pearls are extremely expensive due to their scarcity; prices can range from several hundred thousand to millions of dollars, depending on size and quality.
Natural freshwater pearls
Natural freshwater pearls are formed in a similar manner as natural saltwater pearls, but in freshwater mollusks (mussels) rather than oysters. Natural freshwater pearls are more readily available than saltwater pearls since they are found in freshwater, which is generally more easily accessible than saltwater, and also because mussels, unlike saltwater oysters, produce multiple pearls in a single harvest.
Whether cultured or natural, freshwater oysters typically have less luster and quality than saltwater pearls.
- Size and shape
Compared to saltwater pearls, freshwater pearls are typically smaller in size and have a larger range of shapes. It is difficult to find completely spherical natural saltwater pearls, as it is with natural saltwater pearls.
Natural freshwater pearls are less expensive than natural saltwater pearls, but they are more expensive than the majority of cultured pearls.
Types of pearls (shape)
Pearl shape is one of the key factors in pearl classification because it plays a major role in determining pearl value. There are several terminologies, some more common than others, used in the description of pearl shape. Some of these terms will be examined below in order to give you a good idea of the various shapes pearls come in.
- Round pearls
As its name implies, a round pearl is perfectly spherical in shape. Because it is the most preferred variety of pearl shapes, it is more expensive than other pearl shapes of similar size and origin.
- Near-round pearls
Near-round pearls are almost perfectly round but have a little protuberance that prevents the complete roundness of the pearl. These are considered the next-best pearl shape when round pearls are unavailable or unaffordable.
- Oval pearls
Oval-shaped pearls are pearls with an off-round shape. Pears with an oval shape have ends that are narrower than the middle. They look pretty gorgeous and have a plethora of uses.
- Drop pearls
Drop-shaped pearls get their name from their remarkable resemblance to teardrops. They are even sometimes referred to as “tear-shaped pearls.” They look like ovals, but one end is significantly narrower than the other. They can also be of good value if the shape is perfect. Drop-shaped pearls are often employed in earrings or as a sort of pendant in necklaces.
- Button shaped pearls
Instead of being a perfect sphere, button pearls are somewhat flattened or slightly curved at the bottom, giving them the appearance of a button or even a disk. As the flattened side can be affixed to the setting, these pearls are frequently used in earrings. They also offer great value for those looking for premium pearl jewelry at bargain prices.
- Baroque pearls
Baroque pearls are pearls with irregular, non-spherical shapes. This is due to protrusions on either or both ends of the pearl. Baroque pearls are virtually any pearl that does not have a remotely spherical orientation.
Baroque pearls generally come at a lower cost than round or off-round pearls. However, some prefer baroque pearls because of their unique shapes. The price difference between baroque pearls is determined by color and brilliance. Customers will go to great lengths to get the darker baroque pearls because the white, silver and pink ones are so much more common.
Although baroque pearls come in unique shapes, some are more common than others.
Further classification of baroque pearls according to their shape
- Rice pearls
Rice pearls are elongated freshwater pearls that have a surface structure that resembles a grain of rice. The value of a rice pearl increases with its degree of ovality, especially if it lacks rings or other surface flaws. Because the value of these pearls decreases with the amount of surface wrinkling, they are among the most affordable on the market.
- Keishi pearls
Keishi pearls occur when the oyster rejects the implanted nucleus before the culturing process is complete or when cultured pearls are withdrawn. These oysters ultimately generate pearls without a nucleus that are 100% nacre. Keishi pearls comes in a wide range of colors and are quite shiny. They are irregular “petal” or “cornflake” shaped pearls – the name “keishi” means poppy seed in Japanese. Hence, these pearls are also known as “poppy seed” pearls.
- Heart pearls
Heart-shaped pearls are flat, glossy pearls that have developed a heart shape. They are usually employed in the creation of romantically oriented jewelry. Larger pearls from this group could be utilized to create heart-shaped pendants.
- Coin pearls
They stand out due to their flat, rounded shapes and slick, reflective surfaces. They can be found in different kinds of jewelry, including bracelets, earrings, and necklaces.
- Twin pearls
As the name implies, these are two pearls that have been conjoined during formation to make a single pearl. They can be symmetrical or asymmetrical, and jewelers use them to make stud earrings or necklaces.
- Circled baroque pearls
These are pearls with concentric rings, ridges, or grooves that encircle them. Circled pearls are also referred to as “ringed pearls,” and they are named after the principal shape of the jewel, such as circled round, circled oval, circled baroque, and so on.
These rings or circles were dubbed “circles of love” in the 1970s as a way to advertise these pearls. The surfaces of circle pearls typically exhibit extremely high rates of luster, orient, and overtone saturation.
Pearls are the only organic gemstones that have been highly valued for millennia. They are incredible and fascinating, and they make wonderful gifts for others or yourself. They are particularly suitable as pearl anniversary or 30th-anniversary gifts.
You can now determine which type of pearl appeals to you the most now that you’ve learned about them.