In chapter5 Juana hears the song of Evil. why does she try throw the pearl into the ocean? why did kino react so violently?

Juana believed the evil of the pearl had to be thrust away...... she believed the strife that had entered their lives had to be thrown back where it came from in order for them to regain their own lives.

Kino, on the other hand is obsessed with the pearl. He is no longer the loving husband and father, but rather an obsessed man, who looks to be insane and has become capable of commiting murder.