Pearl Nacre, Judging Nacre of Pearls
The thicker the pearl nacre layer, the more valuable the pearl. Thick, overlapping nacre layers create a strong luster and a valuable pearl. Thick nacre layers take years to build up, and they can also be affected by the oyster's health and the surrounding water conditions.
The nacre layer can be used to determine whether a pearl is real. If you hold a false pearl over a flame, it will produce black smoke—and the outer layer will peel off. Real pearls will not peel or produce smoke.
Nacre thickness is classified using the following standards:
Very thick: A ≥0.6mm
Thick: B ≥0.5mm
Medium: C ≥0.4mm
Thin: D ≥0.3mm
Very thin: E ＜0.3mm
Shecy Pearl Jewelry only sells pearls above 0.5mm in nacre thickness.
Judging Nacre of Pearls
Sometimes you can know the nacre by looking at the pearls to determine if it’s thin or very thin.
• The pearls usually have a low or very low luster and may look milky. Some thin-coated pearls, however, may show a decent medium luster.
• The nacre coating has cracks.
• Areas are visible where the nacre has peeled off.
• Layers of the shell beads are slightly visible when the pearls are suspended and light shines through them. These layers look like curved lines, stripes or wood grain. Usually the thinner the nacre, the easier it is to see the lines. If you can't see any shell layers, this does not mean that the nacre is thick. There are lots of thinly-coated pearls that don't show these layers. However, if you can see them, the nacre is probably too thin.
• As the beads are rolled, some may look light and then dark as the light shines through them. This is because the shell beads may have mother-of-pearl layers that block the light. This phenomenon is called "blinking" and can sometimes be seen in thinly coated pearls.Pearls with thick nacre should not blink.
• A more accurate way of judging nacre thickness is by examining the drill holes of the pearls, preferably with a 10-power magnifier such as a jeweler's hand loupe. Examining drill holes with a loupe will also help you detect dyes and imitations. The drill-hole method is too slow to be practical for dealers, but it is a good way for less-skilled people to estimate nacre thickness. It also allows appraisers to give a more objective measure of nacre thickness.
Ideally, consumers could choose from a wide range of nacre thicknesses and know exactly what they were getting for their money. Since this ideal does not currently exist, it's to your advantage to pay attention to nacre thickness and to learn to detect thin nacre yourself.
Is Nacre Thickness Important and Does it Affect Pricing?
As for price, it has to be affected by nacre thickness. It naturally will cost a farmer progressively more to culture pearls for 6 months, 1 year and 1 1/2 years. The additional cost must be passed on to the buyers.
Often the effect of nacre thickness on price is linked to that of luster. Thicker nacre usually means higher luster, and both bring higher prices. Thickness of the nacre is one of the most important quality of a cultured pearl. It gives color, luster, and appearance. Pearls are among the softest of all gems, and normal body fluids, as well as contact with perfumes, hair sprays, and acids reduce nacre. A thinly coated pearl won't last many years.
