What kind of pearl is this? Amazingly, an X-ray can tell!
This article is about Industrial X-Ray, an area we find interesting in our line of work. We, however, do not offer industrial x-ray services here at Fox Valley Imaging, it a different type of X-ray than machines used on humans. The only sources we are aware of for the x-ray of pearls is the Gemological Institute of America Inc. http://www.gia.edu/gem-lab-service/pearl
Many people have some confusion about different types of pearls. What does it mean for a pearl to be “genuine,” “natural,” or “cultured”? If you are interested in purchasing pearls, how can you ensure that they are of top quality?
To truly investigate a pearl’s type and origin, an X-ray is an indispensable tool. X-rays allow us to see inside the pearl, gleaning detailed information about its origin, type, and value.
Genuine pearls are formed when mollusks deposit a material called nacre around a particle inside their shell. The nacre has a beautiful luster that gives pearls much of their intrigue. Real pearls form in a variety of mollusks (not only oysters) in both salt and freshwater. Imitation pearls, on the other hand, are made from a variety of materials. When buying pearls, you may be able to identify fake pearls simply by name: They might be labeled as simulated, glass, faux, artificial, plastic, roman, resin, man-made, and so forth.
Fake, however, is not the same as cultured. Cultured pearls are formed by a mollusk using the same biological processes that cause the formation of a natural, wild pearl, and they are rightfully referred to as genuine. Cultured pearls, however, get their start through human intervention. A small bead (in the case of a “bead-nucleated pearl”) or a piece of mantle tissue (in a “tissue-nucleated pearl”) is placed inside the mollusk’s shell, triggering the pearl-formation process.
Beyond the diversity in how pearls are formed, some genuine pearls have had coatings or faceting applied, and such treatments may create further confusion for those attempting to evaluate pearls. There are also “shell pearls,” which are created from the shells of mollusks. These are not real pearls because they are not formed by natural processes of nacre deposition within the mollusk.
To cut through this confusion, X-ray technology takes a picture of the inside of the pearl. If the pearl is a natural pearl, the X-ray will reveal the characteristic growth patterns of a natural pearl. If the pearl was cultured, the X-ray can determine whether the pearl is bead- or tissue-nucleated. Bead-nucleated pearls, such as Akoya or South Sea cultured pearls, can be accurately identified in the X-ray by the presence of the bead inside the pearl. However, some cultured pearls are beadless, such as Chinese cultured freshwater pearls, and these too can be identified with careful inspection of the internal structures of the pearl.
Lastly, a pearl may be identified as salt or freshwater based on whether they fluoresce under the X-ray. Saltwater pearls do not fluoresce, while freshwater pearls do.
With all of the varieties of pearls and their differences in value, it is critical to have a way to look below the surface of the pearl. X-rays provide a wealth of information and can reveal the true origin and value of a pearl.