By Renée Newman
Whenever something is prized, it is usually imitated, and pearls are no exception. Fortunately, fake pearls are easier to spot than many other gem imitations.
Putting pearls to the test
The following are some key tests for detecting imitation pearls.
Under 10x magnification, imitation pearls have a grainy, glittery, speckled surface (Figure 1 on the next page). At higher magnification, this may look pitted and resemble the moon’s terrain.
Cultured and natural pearls display a smoother-looking surface under 10x magnification. Curiously, at very high magnification (about 50x and above), pearl nacre has maze-like, scaly patterns similar to the ones in Figure 2, which imitations lack. A fibre-optic light is helpful for viewing these patterns, while diffused fluorescent light makes them more difficult to see.
Magnification is the most reliable method for detecting pearl imitations. Nevertheless, it is wise to use a combination of tests to determine a gem’s identity.