Hi Tinkerbelle. It is recommended that pearls are restrung every couple of years, I think, but I wear mine every day and the weak spot is one pearl in from the clasp where, because of a combination of oils from the skin, perspiration and stress of daily use, the necklace comes apart. This may sound horrendous, but because the pearls are knotted the worst that happens is that the whole thing snakes its way down between my boobs. If the pearls were simply strung without knots they would all fall to the floor. Traditionally, silk was used but I imagine that it has been replaced by something equally strong but man made. Hope this helps.