Madstone with holes

 I found an odd stone.
It had many holes.

 

 

 

 

 

 Was it  a pumice?
It might be not.
It also has shallow hole.

The hole might be dug by organisms.. 

 

 

 

 

 

 

 

I put it on the wet sand on the beach.

It absorbed water with holes.

 

The hole had special role on this stone.