For millions of years rocks have formed the fundament man moves on over the earth. Rocks are everywhere, so they are said to be the memory of our planet. How can a sandstone landscape be pastel pink and another is full of colorful dramatic lines? Why is one basalt boulder rough and porous while another appears as fine and polished as glass? Where do the rich granite boulders come from in an otherwise flat plain? What is the difference between granite and basalt and - why aren't all the craters on earth of volcanic origin? In my trips to spectacular places characterized by highly concentrated deposits of rock - the basalt on the Pacific Ring of Fire, the sandstone in the American West, granite in the cold French Atlantic and the marble quarries in Rajasthan - I find answers.