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Buyer's Guide
Tahitian Pearl Color

When defining the color of a pearl, two major factors are taken into consideration, the bodycolor and the overtone. For white pearls, the color can best be seen when held under direct light on a white background. The center of the pearl, where the light is reflected, will show the overtone. For black pearls, the overtone is more visible under diffuse light. Early theories attributed color formation to factors such as weather, water quality, depth, or sediment. Modern study shows that the color directly relates to both the inner color of the mollusk it forms in as well as the color of the nucleus that is implanted. Pigment is present in the conchiolin layered in and around the nacreous crystals, which can themselves absorb trace elements from the water they grow in. Breeding over the years has produced whiter pearls particularly from Akoya oysters, which can also be enhanced by post-harvest processing. Pearls can be naturally bleached in the sun, but are more often enhanced through chemical processes. Pearls need to be drilled before they are dipped, so that the solutions can penetrate the inner layers of the pearl. Pearls can also be dyed, which often results in color blotches on the pearls surface. A magnifying loupe can also be used on the drill hole, which will often betray irregular stains of color. The most common overtones for white Akoya pearls are pink and silver, though can also be found in green, yellow, cream, and blue. Australian South Sea pearls, from Pinctada Maxima, come in a range of white to gold, with silvery overtones. The most common black Tahitian pearls, from the Pinctada Margaritifera, come in shades of grey to black with overtones in green, rose, peacock, aubergine, blue, and bronze. Freshwater pearls come in a wider range of more saturated colors such as white, pink, peach, lavender, green, and bronze. To view a range of pearl colors for the Tahitian Pearl family, please click this link: Tahitian Pearls and for the Akoya Cultured Pearl click here Akoya Pearls Due to the high variance in color and overtone in these naturally forming gems, the process of matching can be very difficult.

Tahitian Pearl Strength
While the surface of a Tahitian Pearl may be soft, the pearl as a whole is remarkably strong. In fact, early pearl dealers were able to step on a mix of imitation and real pearls, and those that didn’t break were proven to be genuine. A round object will naturally have more strength and resistance to pressure, the curved surface able to disperse the energy. The layers of crystals that make up the nacre, while lightweight, are also very strong. With the addition of conchiolin to the crystal layers, they are also slightly elastic, which provides a cushion when under pressure. These qualities make Tahitian Pearl pearl drilling a difficult process. If done incorrectly, the pearl will fracture or flake. Modern drills support pearls in such a way that the drill can enter both sides the pearl at once.

Tahitian Pearl Hardness
The surface quality of a Tahitian pearl is relatively soft, rating about a 4 on the Mohs scale. (Soapstone rates a 1 as the softest, while diamonds rate a 10 as the hardest.) This means that a sharp object can mark the surface, while a fingernail cannot.

This flame-like pattern appears on pearls that form from fiber-like or prismatic crystals, such as those that come from the conch shells of snails. The visual effect is a result of non-nacreous layers that form perpendicular to the surface instead of parallel.

Luster is one of the most visible ways to measure the quality of a Tahitian pearl. It comes from more than just a surface reflection, and can display the qualities of layers deeper inside the Tahitian pearl. A pearl with a truly high luster will reflect shapes distinctly, as well as have a high contrast between the light and shadowy surface areas. Due to their spherical shape, Tahitian pearls reflect light in a way that produces a glow. The layers of nacre that make up the pearl are composed of tiny nacreous crystals, which have a wide range of translucency. When the pearl is formed, these crystals stack in layers, creating an irregularly shaped surface that can reflect and refract light. This phenomenon is unique to spherical pearls because of the concentric way that the layers form. The intensity of a pearl’s luster is determined by the smoothness of its surface, the thickness of its nacre, the quality of the nacre itself, and the percentage of conchiolin present in the pearls layers, which is opaque and can dull the luster of the pearl. After harvesting, pearls are cleaned, either mechanically or by hand, to ensure that the surface is clear and can be examined for quality. Orient is another term that can be used for the surface quality of a Tahitian pearl, though it is more commonly used in reference to irregularly shaped pearls. It also more specifically refers to the colors that can be seen in the light refracted by the pearl’s nacre. If the layers form properly and are sufficiently translucent, light can refract to produce a very intense iridescent quality.

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