The time period is after World War II, and Steinbeck is disillusioned with a world and a country that could create the atomic bomb. He uses the pearl as a symbol of several things in order to show this. Not only is the pearl a symbol of the effects of greed on man, the pearl and the pearl bed represent the whole European conquest of the Americas and the gold, silver, and other resources they found there. In his story, the pearl symbolizes Kino's and Juana's escape from poverty as victims of colonialism. It's a warning that there's no easy or magical solution to a person's problems.