Pearls, unlike any other gem, are produced by a living creature. Delicate as they appear to be, they should last forever if you follow these simple rules. Marylin Monroe may have worn nothing but Chanel No 5 to bed, but really clever girls know that the only thing to wear in is their pearls as the skin's natural oils give them a special lustre. The maharajah of Nawanagar acquired in the 1930's a fabulous rope of pearls from Cartier and had a favoured black servant wear them as his skin gave the pearls an attractive lustre. So don't be coy, take off the twin-set before retiring, but not the pearls. Store pearls separately from diamonds that could scratch the surface of the pearl. The best idea is to put them in a cloth bag and tuck them away in a corner of your jewellery box. Never ever, spray perfume directly onto the pearls as its acidic nature, and even hairspray, can erode the outer layers. I am so paranoid about getting any perfume on them that I spray the perfume onto my clothes, rather than my skin, when I wear mine. And just in case any corrosive substances, including perspiration, have come into contact with your pristine pearls, wipe them off before putting them away, particularly if it was quite a party. And old make-up caked onto pearls is not a good look. In the case of pearl necklaces, every five years or so take them to a jeweller to check if they need re-stringing. It is a small investment that will save you from that dreadful situation of scrabbling around on all fours retrieving the bouncing orbs from underneath people's feet and behind the sofa, and inevitably loosing some.