Key Takeaways
- Natural pearls come in five main types: genuine cultured, freshwater, Tahitian, Akoya, and South Sea pearls. Learn about their origins, unique beauty, and values below to make an informed purchase.
- Evaluating the quality of a pearl involves examining its size, shape, color, luster, and surface. Check out the step-by-step guide below to understand each factor and learn expert tips for proper pearl care.
Introduction to Natural Pearls
Natural pearls are rare gemstones formed entirely by nature without human intervention. They develop when an irritant, such as a shell fragment or parasite, enters the soft tissue of a mollusk, such as a mussel or oyster.
To defend itself, the mollusk coats the intruder with layers of mother-of-pearl. These layers accumulate over months or even years, gradually shaping a pearl.
A natural pearl is nestled inside an oyster
These types of pearls are perfectly round, often taking unique shapes like drops or baroques. Their color and luster vary greatly depending on the type of mollusk and the environment in which they grow. Different types of pearls range from white, cream, pink, silver, gold, to darker shades like black, gray (gray pearl), and blue.
Due to the long and unpredictable process of their formation, natural pearls are extremely rare and highly prized. Although they can be found all over the world, the most sought-after natural pearls come from regions such as French Polynesia, Japan, Tahiti, and New Zealand.
The Different Types of Natural Pearls
1. Cultured Pearls
Cultured pearls are genuine pearls that form in the soft tissue of a mollusk, guided by human intervention. Unlike natural pearls, where formation occurs by chance, cultured pearls begin with the intentional introduction of a small irritant into the mollusk. The mollusk then secretes layers of nacre around this irritant, thus forming a pearl.
Although natural pearls and cultured pearls share the same composition and appearance, the latter are more affordable due to their human-assisted creation and greater availability. Today, most pearls on the market are cultured pearls, which are popular for necklaces, bracelets, and settings for earrings, rings, and pendants.
Baroque cultured pearls in the gold-plated Molly bracelet by GISEL B.
At GISEL B , our jewelry designs feature cultured pearls from an Asian family farm. These different types of pearls guarantee exceptional quality, contemporary style and luxurious appeal while respecting ecological responsibility.
Explore our exclusive collection to find the perfect necklace, bracelet, earrings and accessories for any occasion, whether it's classic white pearls or the more exotic grey pearls (as Tahitian pearls are often called).
2. Freshwater Pearls
Freshwater pearls are produced by mussels in natural or artificial freshwater environments such as lakes, ponds and rivers, with China being the world's largest producer of these cultured pearls.
Standard Color Shades of Freshwater Pearls
In the classification of pearl names, freshwater pearls are faster-forming, more affordable, generally less lustrous, and of lower quality than saltwater pearls. However, they offer a wider range of sizes, typically from 2.0–3.0 mm to 11.0–12.0 mm, with some experimental varieties reaching up to 15.0 mm.
These pearls naturally occur in a spectrum of pastel colors, including pink, peach, lavender, and white, and can also be dyed in various shades such as black, green, red, and yellow. While the most sought-after freshwater pearls are nearly perfectly round, they also come in symmetrical and baroque shapes.
3. Tahitian pearls
Tahitian pearls, produced by the black-lipped pearl oyster Pinctada margaritifera, native to Tahiti and other islands of French Polynesia, are highly prized for their striking luster and stunning natural colors. They range in hues from subtle blacks and dark grays to peacock greens and purples, often accented with shimmering shades of magnolia, silver, and blue.
Most Tahitian black pearls retain their natural color, requiring only light washing and polishing after harvesting.
Typically, these types of natural pearls range from 8mm to 14mm, but can reach up to 21mm. They come in different shapes, with perfectly round pearls being the most coveted and valuable. Uniquely, Tahitian gray pearls meet internationally recognized quality standards. This type of pearl must have a nacre thickness of at least 0.8mm to be eligible for export from Tahiti.
4. South Sea Pearls
South Sea pearls are primarily harvested in regions such as Australia, the Philippines, Indonesia and Myanmar, using the Pinctada maxima pearl oyster, the largest pearl oyster in the world. Due to the complex culturing process and high failure rates, these pearls are among the most valuable.
The value of South Sea pearls is enhanced by their large size, thick layer of nacre, and the harsh growing conditions they require.
Often called the "Queen of Pearls," South Sea pearls are renowned for their satiny luster and gorgeous colors, including white, gold, and captivating shades of green, blue, and pink. They range in size from 7mm to 20mm, with an average of 12mm. Most of these types of pearls are irregular, making perfectly round pearls rare and expensive.
The name South Sea pearls is synonymous with luxury and rarity, partly because of these unique characteristics and the difficulty of culturing them.
5. Akoya pearls
Akoya pearls come from the saltwater regions around Japan, Korea, China, and Vietnam, and are produced by the small Pinctada Fucata oyster. Due to their limited size, these oysters typically produce only 1-2 pearls per harvest, adding to their rarity and value.
The beauty of white Akoya pearls
Although classic Akoya pearls are typically white, they can also be found in natural shades of silvery blue and gold. These pearls range from 2mm to 10mm and are renowned for their round shape and exceptional mirror-like luster, although irregular shapes are also available. Among the different types of pearls, the gray Akoya pearl is particularly prized for its timeless elegance.
Pearl Quality Criteria
To evaluate the quality of a pearl, consider the following five key factors:
1. Size
The size of a pearl is measured in millimeters based on its diameter. Generally, the larger the diameter, the more valuable the pearl. While tiny pearls can be less than 1 mm, larger varieties, such as South Sea pearls, can reach up to 20 mm. Most pearls range in diameter from 6.5 mm to 11.0 mm.
Even an increase in size of one millimeter can have a significant impact on the appearance of the pearl.
2. Form
A perfectly round pearl is exceptionally rare and, all things being equal, is usually the most valuable shape. However, if you appreciate unique, creative, and free-spirited jewelry styles, pear-shaped, oval, or baroque (irregularly shaped) pearls offer equally captivating options.
(From top to bottom) Pearl types are classified by shape: round, near-round, semi-baroque, and baroque.
3. Chandelier
Luster is the most important factor in defining the beauty of a pearl. It is created when light passes through the translucent layers of the nacre, reflecting from deep within the pearl. The clearer and brighter the luster, providing a clear reflection, the more valuable the pearl becomes. On the other hand, pearls that appear excessively white or dull are considered of lower quality.
(Top to bottom) Japanese cultured saltwater pearls are graded by luster, from excellent, very good and good to fair and poor.
The National Institute of Gemmology evaluates the luster of pearls on a five-point scale:
- Excellent Bright and clear reflection
- Very Good : Bright with almost sharp reflection
- Good : Bright but not sharp, slightly dull at the edges
- Average : Weak and dull reflection
- Poor: Dull and diffuse reflection
4. Surface
The smoother a pearl's surface, the higher its value. However, being organic, pearls rarely have flawless surfaces. They may show abrasions that resemble scratches, a flattened area that does not alter their overall shape, or irregular ridges that resemble folds or wrinkles.
When surface imperfections are numerous or significant, they can affect the durability of the pearl and significantly reduce its value. However, if these features are minor or few in number, especially if a drill hole or mounting can conceal them, they have less influence on the beauty and value of the pearl.
5. Color
The natural color of a pearl is determined by the mollusk that produces it. For example, only Tahitian oysters produce pearls with naturally dark, metallic hues. In contrast, South Sea oysters are known for their rich white and gold pearls, while freshwater pearls offer more variety, often appearing in shades of peach, white, and lavender.
Natural colors of Tahitian, South Sea and freshwater pearls
Additionally, no pearl has a uniform hue. For example, Tahitian pearls are never purely black, but can range from deep green to deep gold, while Akoya pearls come in shades of white, pink, and cream rather than pure white. Additionally, pearls also exhibit tone—a subtle sheen that interacts with light, causing their color to vary under different lighting and angles.
Care and Conservation of Pearls
Quality pearls are very durable, but proper care is essential to maintain their beauty. Here are some essential tips to keep your pearl jewelry in pristine condition:
- Wear them often : Pearls benefit from the natural oils your skin secretes, which helps maintain their shine. The more you wear them, the better they will look.
- Clean gently : After wearing, wipe your pearls with a soft cloth to remove perspiration, perfume, oils or dirt.
Gently wipe the pearls with a soft cotton cloth to avoid scratching their surface.
- Store them carefully : Keep pearls separate from other jewelry, such as sequins, beads, or metallic threads. Wrap them in a soft linen cloth or place them in a soft pouch.
- Avoid airtight storage : Never store pearls in airtight containers like plastic bags. Pearls need moisture, and in environments that are too dry, they can crack. If necessary, place a damp cloth nearby and remove the pearls as soon as possible.
- Avoid Harsh Chemicals : Bleach, hydrogen peroxide, ammonia, vinegar, hair spray, perfume and cosmetics can damage the surface of pearls.
- Remove before physical activity : Remove your pearls before exercising to protect them from sweat.
- Keep them dry : Avoid submerging pearls in water. Do not shower, wash dishes, or swim with your pearls, as chlorine can deteriorate the epoxy that sets the pearls, and soaking the silk thread can cause it to stretch or break.
- Avoid hanging necklaces : Do not hang pearl necklaces on hooks, as this can put pressure on the silk thread and stretch it.
- Re-string them regularly : Do this every two to three years, or even annually. Each pearl should be knotted separately, preferably with silk, to avoid friction and wear. For small pearls, knots between each pearl may be optional.