Treated Pearls

Manufacturers sometimes treat pearls using certain methods to give them a desired surface luster and color depth. They often bleach or polish almost all types of pearls before and after manufacturing to improve their aesthetic value.

There are three types of treatments that pearls usually undergo – dyeing, irradiation and luster treatment. A silver nitrate coating on the nacre of the pearl darkens its color. In the irradiation process, the gamma rays act upon the nucleus to darken it. During the luster treatment, machines use a special coating on the pearl to increase its sparkle.

In today’s market, where pearl treatment techniques are extremely advanced, detecting a treated pearl can be a very difficult task. One basic method is to check the uniformity of the pearls in a single strand. You can suspect treated pearls if you observe a high consistency in the strand, as natural pearls will show more variation.

In recent times, experts have implemented microscopic observation to identify treated pearls. Evidence of an untreated pearl appears in the form of any uncommon, ultrasonic fluorescence reaction.