PEARL QUALITY

Pearls are first classified by origin, then graded by following: luster, nacre thickness, surface clarity, shape, color, size, and matching. These qualities are not considered equal, as some of these factors are weighted to give them more influence in arriving at a final grade. A very thin nacre thickness, for example, could never yield a fine quality pearl.

Grading is relevant to the best attainable quality for each type of pearl. For example, South Sea pearls, which are grown in warmer water for a longer periods of time, generally have a lower luster and more tiny blemishes than Japanese Akoya pearls, that grow in colder water and for shorter periods of time. South Sea pearls are graded against each other, not by what would be expected for a similar quality Akoya pearl.

Pearls should be evaluated on the basis of the following criteria:

1)   Luster – The combination of surface brilliance and a deep, almost three dimensional glow; luster of a good quality pearl should be bright and not dull. You should be able to see your reflection on the surface of a pearl, and one with good luster will have very crisp details in the reflection. Any pearl that appears chalky or dull indicates low quality. Luster, on more scientific terms, is the reflection and refraction of light as it passes through the layers of aragonite crystals, or what we call nacre.

2)   Nacre Thickness – Nacre, pronounced (NAY-kǝr), is the substance that makes up the layers of a pearl over the tissue or bead nucleus. Most often, the thicker the nacre of a pearl, the higher quality it is. A thick nacre generally results in higher luster, and is much more durable than a pearl with thin nacre. This quality is not relevant for Freshwater pearls as they are composed entirely of nacre. Nacre, also known as Mother-of-Pearl, is the platelet combination of aragonite and calcite bonded together by conchiolin.

3)   Surface Clarity – Surface clarity refers to the cleanliness of a pearl’s surface, or to the absence of organic spots, bumps, or indentations. Avoid pearls with cracks or chips in the surface as they will only get larger over time. Look for such damaging blemishes near the drill hole of a pearl. When other factors are the same, a pearl with a cleanesurface is more valuable than a pearl with a blemished surface.

4)   Shape – Since cultured pearls are grown by mollusks and are subject to whims of Mother Nature, it is rare to find a pearl that is perfectly round. Pearls, are generally ranked for quality in the following order: round, near round, drop shape, and baroque; they may also fall somewhere between any of those categories. While round pearls often command the highest prices, asymmetrical and baroque pearls are admired and sought after for their unique shapes.

5)   Color – Pearls are cultivated in colors from white, black, pink, orange, lavender and gold; and can be further enhanced into a variety of trendy hues. Color is more heavily weighed in a natural pearl, but can play a part in the quality of cultured pearls. Generally, the type of pearl factors into how important color is in the quality of the pearl. In Freshwater, pearls with the highest saturation of color will rank higher on the grading scale. In South Sea and Akoya pearls, the more rare the color (like the highly sought after pink body tones) are given a higher quality than say a more typical white or gray body color. Color quality is also based on the overtone of the pearl. The overtone is the faint halo ring of color around the pearl. The overtone has an iridescence or orient that can be one or more colors, and the more intense the orient, the higher the quality of the pearl. More often than not, color can simply be the personal preference of the wearer.

6)   Size – Generally, the larger the pearl, the more value it has, but this is only true if the other quality factors remain the same. A pearl that is 15mm but has very thin, dull nacre will still be low on the quality scale. Sizes of cultured pearls range from 1mm to 24mm in round or symmetrical shapes, and can be well over 30mm in length for baroque shapes.

7)   Matching – Refers to pearls within a strand, pairs of strands, or earrings pairs; it addresses uniformity of color, luster, shape, spotting, and graduation. If colors are intentionally mixed, it refers to the attractiveness of the combination. Even in ‘uniform’ strands, there will be a gradation of size from the center pearl to those at the ends. Each strand has been matched in a specific order by hand to make sure there are no noticeable differences between pearls that are side-by-side, ensuring a smooth blend. Bead stringers not trained in stringing pearls may inadvertently re-string pearls in the incorrect order, disrupting the ‘blend’ of one pearl to the next, and thus, decreasing the value of the strand.