Like shells, at first as sand comes in, he will feel the pain he can not cure. To reduce the pain he continues to lubricate a grain of sand with his saliva and continuously lubricated.
The longer it gets harder and bigger and slicker, However, the longer he begins to relieve his pain, Look at the results, now the pearls are beautiful and big, And of course has a high value.
Source
Beautiful.
Thanks...😊