The following factors are most recognized for determining pearl’s value:
There are four main types of cultured pearls in the market today, each exquisitely unique in character. They are South Sea Pearl, Akoya Pearl, Tahitian Pearl and Freshwater Pearl.
Size of pearl greatly depends on the size of the pearl oyster, hence the type of pearl. Freshwater pearls range in size from about 3.0-7.0mm, Akoya pearls range from about 6.0-8.0mm, while South Sea and Tahitian pearls would range from about 11.0-14.0mm. Price increases with the size. If a pearl size exceeds the normal range of its specific type, its value could go up exponentially.
Main color of a pearl is called the body colour. Typical colors includes white, yellow, pink, silver or black. A pearl can also have a hint of secondary color, named overtone. It is seen when light reflects off the pearl surface. For example, a pearl may appear white in general, but a pink overtone may become apparent when examined more closely.
Luster is what gives a pearl its unique beauty. The thicker the nacre layer, the better the pearl’s ability to reflect light. Richness of luster is also attributed to smoothness of pearl surface, evenness of nacre layer, and content of impurities. Higher luster, greater pearl value.
The closer to a true sphere, the higher the value of pearl. Shapes that are not spherical nor symmetrical are considered inferior. However, non-spherical pearls are sometimes used in special jewelry designs that appeal to many people.
Flaws naturally arise during pearl’s formation, spots and bubbles easily appear in the layering process. Therefore, most pearls never achieve perfection. Highest-quality pearls are those with the smoothest surfaces and fewer number of flaws. Serious flaws might have impact on a pearl’s value and even hardness.