Lustre of a pearl is an important factor in determining its value. By lustre it implies how well a pearl’s surface reflects light. The beauty of a pearl comes largely from its lustre. The high-quality ones give us an illusion of being illuminated from within. They are shiny and reflect objects. The ones with poor lustre have a dull finish and reflect images poorly. Most of these don’t make it to the market as they are valued less.

Nacre surface

Some variety of pearls exhibits sharp lustre than the rest. This is due to the higher amount of nacre secreted by oysters. Nacre is a resilient and transparent substance which allows light to pass through the surface of a pearl resulting in a lavish glow. The rate at which nacre is deposited is directly proportional to the environment in which it is cultivated and temperature of water.

Which type wins in the lustre category?

Oysters residing in warmer climate have a higher rate of metabolism and secrete nacre faster. The following types take up longer duration to develop and hence tend to have high lustre. Click for more info online regarding the lustre of all varieties of pearls.

• Akoya pearl oysters have bright lustre as they secrete smaller aragonite platelets which are laid down slowly and tightly. They are cultivated in China and Japan at cooler water temperatures.
• South Sea pearls are found to be attractive by those who prefer satin-like lustre unlike the glass-like finish of the former.

Origin of Metallic Freshwater pearls

These pearls have a crisp lustre and have a metallic surface. The crystalline layers of these pearls are tightly packed. When light strikes these pearls, a sharp amount of white light is reflected back. These pearls are very rare as they form only 1% of pearl harvest.

There is a bit of an exception in valuing pearl based on their lustre. Keshi pearls are made of 100% nacre. Since higher nacre indicates more lustre, these pearls are considered the most lustrous of the lot and they tend to be less expensive than its cultured counterparts.