Before trying to evaluate a pearl, you should know what type of pearls it is. Each type has its own characteristics due to the specific forming condition. We normally classify pearls by origin, then grade them within the types they subjected to by luster, nacre thickness, surface quality, size, color and shape.
If you try to compare the luster of a South Sea pearl and an Akoya Pearl, it is possible that you will be disappointed with the former. Why? Because Akoya pearls are very famous for their outstanding brilliance, while South Sea pearls are much bigger than Akoya pearls.
The pearl grading factors are normally not considered equal. Some factors will be weighted to give more influence in arriving at a final grade. Grading is relative to the best attainable quality for a certain type .
Luster and Nacre
Pearl luster - the brilliance and the soul of pearls. This chief evaluating factor separates the inferior pearls from the superior and the ordinary from the extraordinary.
Nacre - you may not directly see how the pearl nacre effects the beauty and value of pearls. But it does! A very thin nacre thickness could reduce pearl luster, color evenness and durability and could never make a fine quality pearl. Freshwater pearls have a very thick pearl nacre. Akoya pearls nacre are the thinnest among all types of pearls.
Making perfection is obviously not the goal of Mother Nature. Surface imperfections are part of a pearl's natural texture and proof of the pearl's genuineness. Even though a pearl is considered more valuable when the surface imperfections are minimal, we should positively consider them more than negative when evaluating pearls. more
Pealrs come in a wide variety of colors, ranging from white all the way to black. The natural color of pearls results from a combination of body color, overtone and iridesence. The wearer's preference determines what color is the best for him/her. Fashion trends and color demand effects different color pearl prices. But it is still important to find a color that is rich and evenly distributed on the pearl. more
Prices go down the line of different shapes. Perfectly round pearls are rarest and most valued. Symmetrical pearls are more valuable than baroque. However, baroque pearls, with their various shapes, can inspire talented jewelers or artists and be created into some amazing arts. more
Knowing pearl types is the precondition of evaluating pearls. Each type of pearls has its own characteristics and valued standards. Among different types of pearls, saltwater pearls are more valuable than freshwater pearls. Natural pearls cost more than cultured pearls. more
Most of the pearls we see are treated more or less. Pearl treatment is a must process before these beautiful gemstones are put on the market. There are many methods to treat peard including polishing, bleaching, dyeing, filling, irradiation, coating and oiling...Treated pearl doesn't mean low quality. People use an exquisite craft to make pearls perfect. This is comparable to that of a diamond that can be called a diamond only after it is cut according to the rock's characteristics. more
The larger the size, the higher the price. But price jumps between pearl sizes are often uneven. Large pearls are more difficult to cultivate because of the large size of the implanted nucleus. There is an increased likelihood that the oyster will reject the nucleus.