how do oysters make pearls – Extreme Temperature Zone

Question: how do oysters make pearls
- Keywords:
  animal,
  material
Asked by Kirito to Jos, Kate, Lisa on 20 Nov 2014.
- Joshaniel Cooper answered on 20 Nov 2014:
  
  when an oyster gets a piece of sand or something else trapped in its shell, it is like a little splinter for it. So to protect itself (and to stop it itching) it covers the sand in a layer of the same stuff it coats the inside of its shell with (called nacre I believe). As the oyster grows, it keeps coating its shell and the little pearl in nacre and the pearl grows bigger.
- Kate Dobson answered on 20 Nov 2014:
  
  Oysters are not the only type of mollusc that makes pearls. Clams and mussels do too, but not as often. Oysters are a kind of aninmal called a bivalves (two valves or shells) and an organ called the mantle is what they use to grow their shells. When something irritates the mantle the oyster tries to cover up particle that is beint ititating by growing entra “nacre” (the shell material) which build up over the particle making the pearl.

Question: how do oysters make pearls