The Brilliance of Pearls
The brilliance of a pearl is closely linked to its surface: an imperfect or marked surface negatively affects its brilliance, determining the overall quality of the pearl.

The AAA classification system is used to evaluate freshwater pearls, assigning them a score ranging from A (the lowest score, with over 25% of the surface affected by defects) to AAA (the highest score, with at least 95% of the surface defect-free). Instead, the A-D classification system (also known as the Tahiti system) evaluates pearls on a scale from A (the highest score, with imperfections less than 10% of the surface) to D (the lowest score, with imperfections occupying over 60% of the surface).

The most precious types of pearls are generally determined by their rarity, beauty, and origin. Here are some of the most renowned types:

1. Saltwater Pearls:
   • Akoya Pearls: Primarily cultivated in Japan and China, Akoya pearls are widely considered among the most classic and refined. They are known for their bright white color and luster.
   • South Sea Pearls: Cultivated in the waters of the South Sea, these pearls are famous for their large diameter and hues ranging from white to golden to pink.
   • Tahitian Pearls: Mainly cultivated in the waters around French Polynesia, Tahitian pearls are famous for their wide range of natural colors, which can include shades of gray, black, green, blue, and purple.

 

2. Freshwater Pearls:
   • Freshwater Pearls: Primarily cultivated in China, freshwater pearls are appreciated for their variety of shapes, sizes, and colors. They can be white, cream, pink, or even purple.
   • Biwa Pearls: Originating from Lake Biwa in Japan, these pearls are known for their irregular shape and unique luster. Although less common today, Biwa pearls are still considered highly prized.

 

3. Natural Pearls:
   • Natural pearls are the rarest and most precious, as they form spontaneously without human intervention. Their production is extremely limited, making them highly valuable objects. Natural pearls can come from wild oysters, such as pearl oysters or freshwater mussels. The waters of the South Sea, including places like Australia and the Pacific islands, are renowned for their production of natural pearls.

Marine pearl oysters are often more noted for producing high-quality and valuable pearls. Some of the most important marine pearl oyster species include:

1. Pinctada maxima: Also known as the Australian pearl oyster or South Sea pearl oyster, this species is one of the main sources of natural and cultured pearls. It is widespread in the South Sea, northern Australia, and other regions of the Indo-Pacific.
2. Pinctada margaritifera: This species is commonly called the black pearl oyster of the Pacific waters and is renowned for producing Tahitian black pearls. It is native to the waters of the Indo-Pacific, including the Pacific islands and French Polynesia.
3. Pinctada fucata martensii: Known as the Japanese pearl oyster, this species is primarily cultivated in Japan and produces Akoya pearls, appreciated for their luster and brilliance.

Freshwater pearl mussels are another important source of pearls, often used in the production of freshwater pearls. Some species of freshwater pearl mussels that produce pearls include:

1. Hyriopsis schlegelii: This species of freshwater mussel is commonly cultivated in China for the production of freshwater pearls.
2. Cristaria plicata: Another freshwater mussel widely cultivated in China for the production of freshwater pearls.

In addition to their origin, other factors that influence the value of pearls include their shape (round pearls are generally rarer and more valuable), luster, surface, and consistency. High-quality pearls feature a smooth and uniform surface, brilliant luster, and rich, vibrant color.

Pearl Surface
The surface of pearls is another crucial aspect to consider: a clean surface free of defects indicates a higher-value pearl. Quality is determined by carefully observing the surface characteristics of the pearl, identifying any visible defects such as spots, wrinkles, deposits, streaks, and protrusions. Since pearls are natural gems, it is normal for them to have imperfections, albeit minimal; however, if these imperfections are negligible, they will not be visible when the pearl is worn.

Pearl Shape
Shape represents a fundamental factor of value: round pearls are generally the most appreciated, but there are also baroque, semi-round, drop-shaped, oval, and ringed pearls.

Pearl Color
Pearls come in a wide range of colors. It is important to distinguish between the color of the pearls themselves and the reflection. Among the colors of pearls are white, champagne, salmon pink, peach, lavender, aqua green, green, golden, and black, each of which can have multiple reflections and subtle variations in surface iridescence.

Pearl Size
Finally, size represents another factor of great importance. Pearls from the South Seas, which can reach a diameter of 20 mm, are considered among the most precious. However, the most common pearls have an average diameter ranging from 6.5 to 7 mm.