are a natural material that are formed when an irritant finds its way into a living oyster. The oyster protects itself by coating this intruder with a secretion called nacre. This is, in fact, the same material the oyster uses to grow its shell. The irritant becomes trapped within the coating, and over time, becomes what we call a pearl. When pearls are stored in very hot, very dry conditions, the moisture evaporates out of the nacre, causing the pearl to lose its luster/shine, change and dull its color, and the outer covering of the nacre will crack. Sadly, there really is no easy way to restore a damaged pearl. The best storage for pearls is in silk where air can circulate and pearls can "breathe." You can read more about this organic gemstone in the article, For the Love of Pearls!