Without paying a fortune for them, where are some good places in the Bay Area to pick up chiseled granite rocks with interesting patterns and shapes? I am probably not interested in anything over 200 pounds. I want rocks that have jagged edges and surfaces that are worn down by the ages.

This is a photo of a typical kind of rock I might find interesting, particularly the rock on the right side. The rock on the left side looks more dropped down on top of the garden. It's a bit tall and its left side is a bit plain. The rock on the right is sunk into the earth and every angle on it is interesting and more complex.