In the latest Ask Anna column, Andrea L. Dono asked about what to look for in quality pearls, and how to recognize low quality. Joe Ducey, an ABC reporter out of Phoenix, recently investigated one cause of low-quality cultured pearls, and how to detect it.

According to Craig Lynch, the director of the Arizona Jewelers Association, cultured pearls are created by inserting a mother-of-pearl bead into an oyster. The bead is left in the oyster for two to six years, allowing a thick coating to form around the bead. However, when pearls are in high demand, they may be prematurely removed after only three to six months. The resulting coating is thin and can chip or crack.

To tell if a pearl is premature, Lynch advises you to look for “stripes you can see within the pearl, the lack of luster, and noticeable blemishes.” Quality, mature pearls, on the other hand, will exhibit even roundness and a shiny luster free of blemishes.

To get further details about buying quality pearls, read Anna’s response to Andrea’s question. You can also read (or view) the entire ABC report.