How long does it take to make a water pearl and how?

Question: How long does it take to make a water pearl and how?
- Keywords:
  pearl,
  water
Asked by Jessica209 to Karen on 15 Nov 2018.
- Karen answered on 15 Nov 2018:
  
  It takes about 6 years! When a parasite (a bug) or a bit of sand gets into the mussels shell, it surround the sand with a liquid called nacre that hardens over time into a tough pearl, they do this to protect themselves! Pearls are usually stuck to the shell where they won’t harm the mussels body 🙂

Question: How long does it take to make a water pearl and how?