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How to Grade Pearls

Several value factors determine a pearl’s grade and its value. We look at a combination of factors when determining the grade of pearl jewelry.

uster - is quality of a pearl that shows its mirror- like reflecting ability
. Found on the very surface, it is measured by the sharpness and brilliance of the reflection.  A good quality pearl, like a diamond, is one that captures light well and reflects it back to the eyes of the observer in a strong and sharp manner. Grades of pearl luster are: Very High (AAA), High (AA), Medium (A) and Soft (B). Pearls are said to have high, or very high, luster when the reflections are bright and sharp When the light reflections are weak and fuzzy (or diffused), the pearls are described as soft or dull. Dull luster pearls are rejected.  Lustre plays a huge impact in the beauty of a pearl. High luster produces redeeming value even if the pearl fails in size, shape, color and surface.
Surface Quality -This quality is probably the most obvious and easiest to observe. Just touch the pearl and look for blemishes and imperfections like spots, cracks, discolored portions, areas of low or uneven nacre appearance, or any other flaw that can be found. The ideal good quality pearl is one that is free of imperfections. Unfortunately, Mother Nature does not allow it to happen all the time. Slight changes in the underwater environment during the nucleation process affect the layering of the nacre, ultimately creating imperfections. Quality decreases as imperfection increases.

Shape - Pearls are developed in all shapes especially freshwater and Tahitian pearls. They can be round, semi-round, drop, oval, half-rounded, and all kinds of baroque shapes. The general rule of thumb is, the rounder - the better the quality, given that other factors are equal. A pearl is considered  round if it has an almost perfect spheres whose diameter variation rate is less than 2%. The round pearl is the most rare and most beautiful, thus the most sought after.  Semi-round pearls are slightly imperfect spheres whose diameter variation rate is greater than 2% but less than 5%. Also called as off round or near round.

Color -
The color of a pearl is a combination of two components; its predominant basic body color and its overtone. The body color of a white pearl may appear in white, pink, cream or golden, with an overtone of pink or silver. An overtone is the color that overlies the body color resulting from the layers of the nacre, and may be seen under different angles of the light. Every pearl developed appears in different color combination, which makes it truly unique from other pearls.  

Size - Measuring the size basically means measuring the diameter of the pearl expressed in millimeters. Round and off round pearls are measured by the shortest diameter. All pearls in other shapes are measured along two diameters (the longest and second longest). Size alone however is not enough to tell the quality of the pearl. Given that other factors are equal however, the value of the pearl rises gradually with size.  


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