There are many imageries in The Pearl. Let me give you two of them.
First, we have the image of the pearl itself. This is most used and powerful imagery. On the one hand, the pearl is an image of nature. Kino, a pearl diver, finds a pearl; it is as simple as that. Moreover, he finds his livelihood in finding pearls. He lives off nature. This fits in nicely with is brush house and interaction with the ocean.
On the other hand, Kino sees that the pearl is actually more than nature, because it is a pearl of great price. So, in this pearl he sees wealth, a better life, schooling for his son, and so much more. Others want this pearl as well. Hence, greed creeps into the picture.
Another image is Kino's canoe. It has been passed down from generation to generation. It is his the way he makes a living. It is his connection with the past. So, when the canoe breaks, it is symbolic. There is a break with his past, and he will try to seek something more.