2022.08.15
All about pearls：About the brilliance of pearls

Luster is the most important characteristics of a pearlʼs quality.

The better the nacre quality of the pearl, the more superior its luster. A pearl has a layer of calcium carbonate crystals that forms around the nucleus, which is the nacre layer. The nacre layer has a brick-like structure, and the gaps between the layers are filled with protein, which is the secretion of oysters. Pigments are contained in this protein, which is said to be the actual color of the pearl and are making the color of the pearl body.

When light from the outside reaches the nacre layer, it hits the nacre layer, partly it is reflected, and partly it passes through. Part of the light that passes through is reflected by the next layer, and part of the light repeats passing through, and the light reflected by each layer creates each wavelength. The wavelengths interfere with each other and are strengthened or weakened. Colors created by the reflection and interference of light are called “interference colors”. The color of a pearl is made up of “body color” and “interference color”, and rainbow-colored brilliance of a pearl is “interference color”.If the nacre layer is thick and well-ordered, the light refracted by the nacre layer will bestrongly reflected, resulting in a strong luster and interference color. If the quality of the nacre is poor, such as when the nacre layer is thin or uneven, the reflection of light will be dull, and the luster and interference color will be weak. In order to obtain pearls with good luster and interference colors, it is important to ensure that the nacre layer is thick and the crystals are aligned to form layers. However, even if the nacre layer is thick, beautiful luster will not come out unless the nacre layers are arranged neatly.

To distinguish pearls with good luster, it is said that the clearer the image reflected on the surface, the better the luster.