Taking a picture of something is an affirmation. It is a statement of the importance of the existence of the thing. It alters the object’s mode of interaction with the world and it then becomes an object for reflection. For example, a hammer in its usual relation to the environment is as a tool for hammering. When it is needed, it is picked up and used, and then forgotten about until it becomes useful again. If a photograph is made of the hammer, though, it becomes an object of reflection. Rather than just picking up the hammer and using it, the image forces us to think about what hammers are used for, what their existence consists of and means. It is because of this photographic alteration that rocks are a particularly good subject for an exploration of the idea of existence.