Pearl Quality

The visual appeal of a pearl is universally consider to be owed to a variety of features such as body color, shape, luster, surface iridescence that is essentially an overlay to the body color of the pearl, as well as the presence of any subsurface iridescence, which is usually quite subtle and referred to as orient.

Unlike other gemstones, there is no official quality grading system for pearls. However, the price of a pearl is determined by much more than its color, size or shape. There are some key components to grading the quality, and implicitly determining the price, of a pearl.

• Luster should be one of the primary concerns when determining the quality of a pearl. The clearer the reflections on the pearl’s surface, the better the luster. Pearls that have a high degree of luster will be much more valuable.
• In terms of size, the larger the pearl is, the higher its value since larger pearls are quite rare. Pearl size is measured in diameter and can range from 2 mm to over 20 mm, with the latter being highly rare and extremely valuable.
• Shape. Spherical pearls are the most prized, therefore the closer to a perfect sphere the pearl is the higher its value will be. However, pearl shape is also determined by class, therefore when it comes to Baroque pearls, which are more linear and have irregular shape, the more unusual the shape the higher the value will be.
• The fewer blemishes the surface of a pearl has, the more valuable it will be. Since a pearl is the result of a natural process, only about one in a million pearls are completely flawless as the oyster usually leaves some type of mark on the finished pearl.
• Color has little impact on the value of a pearl other than popularity. Of course, color treated pearls will be of lesser value than natural pearls, such as in the case of golden South Sea pearls which are often treated to obtain the gold hue.
• Natural versus cultured. Natural pearls are quite rare nowadays, making them extremely valuable. However, one shouldn’t purchase a natural pearl without an accompanying gemological certificate stating that the pearl has undergone an x-ray procedure and has been determined to be natural.
• Weight is also a factor in determining the quality of a pearl. The latter is not always provided but some jewelers will have the information available. Natural pearls are weighed in momme, cultured pearls in grains, and the rare conch pearls in carats.
• Rarity. The more difficult it is to find or farm a certain type of pearl, the higher the value of that pearl will be.
• Orient. This rainbow effect caused by the multiple layers of nacre is not a common occurrence in pearls and thus will increase the value of the pearl.
• Uniformity. The value of pearl jewelry increases with the uniformity of the pearls. Thus, the closer they are in size, shape, color, luster and so on, the higher the price the piece will command.