There are many different ways to make breccia, and usually geologists add a word to signify the kind of breccia they're talking about. A sedimentary breccia arises from things like talus or landslide debris. A volcanic or igneous breccia forms during eruptive activities. A collapse breccia forms when rocks are partly dissolved, such as limestone or marble. One created by tectonic activity is a fault breccia. And a new member of the family, first described from the Moon, is impact breccia. This specimen, in Upper Las Vegas Wash in Nevada, is probably a fault breccia.
Some big close-up pictures of breccia are available as free wallpaper images.
For more photos see the Sedimentary Rocks Gallery.
Other galleries:
Fossils
Geologic Features and Processes
Glaciers and Ice
Landforms
Minerals
Rocks
Geology and Society
