Michael Krzemnicki, director of the Swiss Gemmological Institute (SSEF), is warning the jeweler trade about a new, artificial unstable resin coating that is damaging conch pearls when applied. The damage done to the pearls is devastating and practically irreversible. Upon examination of some contaminated pearls, Krzemnicki noticed that the pearls were covered with whitish crust. The owner of the pearls in question stated that they were worn rarely and were kept in a safe.
The laboratory team over at SSEF then compiled a scanning electron microscopic analysis of these same conch pearls. The results concluded that the conch pearls had been coated with a carbon-rich layer, or artificial resin. The SSEF lab presumes that the whitish crust was most likely caused by the de-gassing on the carbon-rich coating that was applied to the pearls. Krzemnicki says, “This process, in the end, results in the precipitation of a whitish encrusting on the surface. It seems that only a thorough reshaping and re-polishing can remove the damage”
How To Know Which Conch Pearls Are Contaminated
Upon further inspection on the conch pearls the SSEF lab found that beyond the noticeable surface alterations, nothing else seemed to be damaged at first glance. However, the lab soon discovered that the coating damages the pearl in stages. The pearls color will begin to wane and take on a dull shade. From there the colors will slowly alter to whitened surface, before becoming corroded with whitish precipitates.
The lab encourages jewelers to use Raman spectrometry to detect the carbon-rich layering on the pearls. The lab confirms that this is the best method to use in detecting this particular treatment. Krzemnicki warns jewelers that even a perfect looking pearl may still be coated in this damaging artificial resin. The SSEF lab notes that even the “perfect” looking pearls that are coated in the resin will have a luminescence band that is not seen on uncoated conch pearls.
With this new finding SSEF Director Krzemnicki has added this testing to the lab’s standard analytical procedures for conch pearls. The reports for these conch pearls will say, “treated conch pearl, with this additional statement, indications of surface coating. This coating is not stable and may deteriorate the conch surface in the course of time”.
Jewelers Are Urged to Check Conch Pearls For Resin Coating
Krzemnicki reminds jewelers that the deadliest danger about the coating is that the damage is seen over a period of time. Hence, jewelers may accidently sell a damaged pearl to a consumer that seemed in perfect condition at the time. Selling a damaged pearl can impact the trust of the consumer as well as hurt the jewelry trade, if jewelers are not careful.
Krzemnicki notes that, “by clearly labeling this new and unstable treatment on our reports, we are determined to support the trade to take the necessary measures against this new threat and to prevent a further infiltration of those coated conch pearls into the market”. Let Raymond Lee Jewelers, South Florida’s trusted Jewelry Sales and Service Center since 1983, help you pick out the perfectly non-coated pearl. Raymond Lee Jewelers carries an extensive collection of designer and vintage jewelry, and GIA certified diamonds. Raymond Lee also provides watch repair service and jewelry customizations.