To understand what actually happened, you also must understand how necklaces are made and what extended wear will do to them.
It probably is not a stretch to say that if you're talking about chains, the thinner the chain - the easier it breaks. That should be a given law of wearing jewelry, and I bet you understand that very easily.
An entirely different thing alltogether is a pearl necklace or a beaded piece of jewelry. They look so strong, so enormously sturdy, made for generations to wear, right?
Let me explain.
When we string beads, we always try to make it as durable as possible. So many factors are contributing to their premature breakage though.
Consider this: every time a pearl (or bead) necklace is strung, we are using the thickest cord possible that will fit through the bead. That said, you can look at your beads and figure out how much weight such a relatively thin string can bear.
For good reason: Centuries ago, pearls were traded by weight (actually "grains"). So it's pretty much a given that the holes are drilled relatively small to conserve weight and therefore achieve a higher price.
You can see where this is going, right?
The smaller the hole, the thinner the string. Plus, you don't really want a very heavy cord running through them. as you are having knots in between the pearls, it just doesn't look as nice to have a big blob of cord between each pearl.
The same is true with South Seas or Tahitian pearls. Big, heavy pearls with thin, weak string = disaster!
Not so fast...
It actually takes quite a bit of abuse to break a pearl cord. Typically, when you use silk (or Nylon), these will stand up quite well to chemicals such as make-up, perfume & Co.
Now it's a different ball game when you have stone or metal beads. Often they have rough edges on their holes and that will abrade your bead cord. Add to that a hefty weight plus constant movement on your body, and you can imagine that "forever" is just not in the vocabulary of your beaded necklace.
So it pays to be vigilant: observe your pearls/beads. If they look frail, have them restrung. If they have stretched, have them restrung. If the cord/silk is soiled, have them restrung.
Keeping an eye on your favorite adornments makes it worthwhile to enjoy them for years to come.