Petrography rock was affixed to a microscope slide and then ground so thin that light could be transmitted through mineral grains that otherwise appeared opaque. The position of adjoining grains was not disturbed, thus permitting analysis of rock texture. Thin section petrography became the standard method of rock study. Since textural details contribute greatly to knowledge of the sequence of crystallization of the various mineral constituents in a rock, petrography progressed into petrogenesis and ultimately into petrology. It was in Europe, principally in Germany, that petrography advanced in the last half of the nineteenth century. The macroscopic characters of rocks, those
What Is the What "we really hadn’t decided whether I was just helping Valentino write his own book, or if I was writing a book about him." Valentino points out that, "I thought I might want to write my own book, but I learned that I was not ready to do this. I was still taking classes in basic writing at Georgia Perimeter College." Dave Eggers discusses the difficulties in writing a book of this nature: "For a long while there, we continued doing interviews, and I gathered the material. But all along, I really didn’t know exactly what form it would finally take—whether