Buyers Guide to Pearls

Formation and Cultivation of Pearls

Pearls are formed inside mollusks, such as oysters or mussels, when an irritant like a grain of sand or a parasite becomes trapped inside the shell. In response, the mollusk secretes layers of nacre, a combination of aragonite and conchiolin, around the irritant to protect itself. Over time, these layers accumulate, forming a pearl. Natural pearls occur without human intervention and are extremely rare, while cultured pearls are formed with human assistance by intentionally placing an irritant into the mollusk. Cultured pearls are farmed in both saltwater and freshwater environments, with the mollusks carefully monitored to ensure the successful growth of pearls.

History of Pearls

Pearls have a rich history that dates back thousands of years, often regarded as symbols of purity, wealth, and status. Ancient civilizations, including the Egyptians, Greeks, and Romans, prized pearls as valuable and sacred gems. In the Middle Ages, pearls were associated with royalty and were used to adorn crowns, garments, and religious artifacts. The discovery of abundant pearl beds in the Persian Gulf, India, and the Red Sea made pearls a central trade commodity, further enhancing their allure. The development of pearl cultivation in the early 20th century by Kokichi Mikimoto revolutionized the industry, making pearls more accessible and solidifying their place in the world of fine jewelry.

Difference Between Freshwater and Cultured Pearls

Freshwater pearls are formed in freshwater mussels, primarily in rivers and lakes, and are known for their diverse shapes, sizes, and colors. Cultured pearls, on the other hand, can be formed in both saltwater and freshwater environments. While all freshwater pearls are cultured, the term "cultured pearls" often specifically refers to those formed in saltwater, such as Akoya, Tahitian, and South Sea pearls. Freshwater pearls generally have a softer luster compared to the sharper, more reflective luster of saltwater cultured pearls. Additionally, freshwater pearls are typically less expensive due to their greater abundance and simpler cultivation process.

Significance and Uses of Pearls

Pearls have long been associated with elegance, purity, and wisdom, making them a popular choice for bridal jewelry and gifts that mark significant life events. Their timeless appeal and natural beauty have made them a staple in both traditional and contemporary jewelry designs. Beyond adornment, pearls have also been used historically in medicine, believed to have healing properties and to bring balance and tranquility to the wearer. Their significance extends into various cultural and religious contexts, where they symbolize purity, innocence, and wealth.

Types of Pearls and What Makes Them Unique

Several types of pearls are highly valued for their unique characteristics:

• Akoya Pearls: These are classic saltwater pearls known for their perfectly round shape, mirror-like luster, and relatively small size. Akoya pearls are typically white or cream-colored, sometimes with rose, silver, or ivory overtones.

• Tahitian Pearls: Originating from French Polynesia, these saltwater pearls are renowned for their dark, exotic colors, ranging from black and gray to green, blue, and purple. They are larger than Akoya pearls and are highly sought after for their natural, rich hues.

• South Sea Pearls: These pearls are among the largest and most valuable, primarily produced in Australia, Indonesia, and the Philippines. They are known for their luxurious, satin-like luster and come in shades of white, silver, and golden.

• Freshwater Pearls: Cultivated mainly in China, freshwater pearls come in a variety of shapes and colors, including white, peach, pink, and lavender. They are generally more affordable and versatile, often used in fashion-forward and artistic jewelry designs.

• Biwa Pearls: Biwa pearls are a type of freshwater pearl that originated from Lake Biwa in Japan, one of the largest freshwater lakes in the country. These pearls gained fame in the mid-20th century for their high quality and unique, irregular shapes. Unlike traditional round pearls, Biwa pearls are often elongated, baroque, or stick-like, which adds to their distinctive charm. They were produced by inserting a piece of mantle tissue (without a nucleus) from a donor mollusk into a freshwater mussel, which would then form the pearl. The term "Biwa pearl" has since become synonymous with high-quality, irregularly shaped freshwater pearls, even though environmental pollution has greatly reduced pearl production in Lake Biwa itself. Today, Biwa-style pearls are often cultivated in China using similar methods.

• Coin Pearls: Coin pearls are another unique type of cultured freshwater pearl, named for their flat, disc-like shape that resembles a coin. These pearls are formed by inserting a flat, round nucleus into the mollusk, around which the pearl forms. Coin pearls can be found in a variety of colors, including white, pink, peach, and lavender, and often have a high luster with smooth surfaces. Their unusual shape makes them particularly popular in modern and artistic jewelry designs, as they can be used to create striking, contemporary pieces that stand out from more traditional round pearls. Coin pearls are valued for their versatility and the elegant, minimalist aesthetic they bring to jewelry.

• Keshi Pearls: These are small, baroque-shaped pearls formed as a byproduct of the pearl culturing process. Keshi pearls have a unique, organic shape and exhibit a high luster, making them popular for creative and unconventional jewelry pieces.

• Mabe Pearls:  Mabe pearls are a unique type of cultured pearl, known for their distinctive half-dome shape. Unlike typical round or baroque pearls, Mabe pearls are grown against the inner shell of a mollusk rather than within its soft tissue, resulting in their characteristic flat back and domed front. 

Each type of pearl has its distinct charm, influenced by factors such as origin, environment, and cultivation methods, contributing to their individual allure and significance in the world of jewelry.

How can you tell the difference between a genuine pearl and an imitation pearl?

Distinguishing a real pearl from a synthetic or imitation pearl can be done through several methods, some of which can be performed at home, while others require professional evaluation. Here are some common ways to tell the difference:

1. Surface Feel and Texture (The Tooth Test): One of the most straightforward methods is the "tooth test." Gently rub the pearl against the edge of your front teeth. A real pearl will feel slightly gritty or sandy due to its layers of nacre, while a synthetic or imitation pearl will feel smooth or glassy.

2. Luster and Iridescence: Real pearls have a deep, rich luster and a subtle iridescence that changes when viewed from different angles. Imitation pearls often have a dull or overly shiny surface that lacks the depth of a real pearl’s nacre.

3. Weight: Real pearls tend to be heavier than synthetic or plastic pearls. If you have a strand of pearls, compare the weight to a known real or fake pearl strand to see if there’s a noticeable difference.

4. Magnification Inspection: Under magnification, real pearls show fine surface ridges and irregularities due to the natural formation of nacre layers. Synthetic pearls often have a smooth, uniform surface with no such imperfections. Additionally, real pearls might have small inclusions or tiny bumps.

5. Drill Holes: Examine the drill hole where the string passes through the pearl. On real pearls, the nacre around the hole may show concentric rings or slight chipping. In synthetic pearls, the hole is often more perfect, with a lack of chipping and a plastic or glass appearance underneath the surface layer.

6. X-ray Test: An X-ray can definitively distinguish between real and synthetic pearls. Real pearls show concentric growth rings or a solid structure, while synthetic pearls may show a uniform density or reveal a different material at the core.

7. Touch Test: Real pearls feel cool to the touch when you first pick them up, warming slowly with your body heat. Synthetic pearls often feel warm or room temperature from the start due to their plastic or glass composition.

8. Comparison with Known Pearls: Comparing the pearl in question with a known genuine or synthetic pearl can also help in identifying differences in luster, weight, and feel.

For an accurate determination, especially if the pearls are valuable or part of a significant purchase, it's recommended to consult a professional jeweler or gemologist who can use specialized tools and techniques, such as spectroscopy or X-ray analysis, to confirm the authenticity of the pearls.