Question: What do you think is the most interesting thing about rocks?

David Pyle answered on 20 Mar 2011:

Ahh.. where to start? For me, it is the geological story they contain. Rocks tell us about the history of the planet; the story of ancient oceans and atmospheres; the rise and fall of ancient mountain belts on long-forgotten, or undiscovered, lands. They tell us about the climate of the past and present; the first steps of land animals, the greening of the planet, the rise of our ancestors, the slow cooling of the interior, the ebb and flow of glaciers and the long slow passage of time..