Pearls are the world’s only organic gemstone, and therefore, tend to be quite delicate. Proper care of your pearl jewelry is essential to ensure your investment will last a lifetime. Personal care products, such as perfume or hairspray, can severely damage the luster and beauty of a pearl. It is best to put your pearls on at least 30 minutes after applying any personal care products, and to take your pearls off before getting ready for bed. A good rule of thumb to remember is that pearls should be the last thing to put on and the first to take off. Wiping the pearls with a damp, soft cloth after you wear them will ensure that they remain free of harmful build-up of compounds that may damage the nacre of your pearls. Pearls are best kept in a soft-cloth pouch or a soft-lined jewelry box separated from other jewelry. If you wear your pearl necklace often, it should be strung about once a year to prevent strand breakage. The thread, which silk is the best choice, should be knotted between each pearl to prevent all the pearls in a strand from falling off should a break occur as well as preventing possible damage from the pearls rubbing against each other. Restringing the pearls is preferred over attempting to wash the thread, as cleaning may weaken or stretch the knots and some soaps may be abrasive and damage your pearls.