Petrology Petrology Petrology (from the Greek πέτρος, "pétros", "rock" and λόγος, "lógos", "subject matter", see -logy) is the branch of geology that studies rocks and the conditions under which they form. Petrology has three subdivisions: igneous, metamorphic, and sedimentary petrology. Igneous and metamorphic petrology are commonly taught together because they both contain heavy use of chemistry, chemical methods, and phase diagrams. Sedimentary petrology is, on the other hand, commonly taught together with stratigraphy because it deals with the processes that form sedimentary rock. Lithology was once approximately synonymous with petrography, but in current usage, lithology focuses on macroscopic hand-sample or outcrop-scale
What of the Mormons? What of the Mormons? What of the Mormons?: A Brief Study of the Church of Jesus Christ of Latter-day Saints is a 1947 book by Gordon B. Hinckley that was published by The Church of Jesus Christ of Latter-day Saints (LDS Church). Portions of the book continue to be published by the LDS Church under the title Truth Restored: A Short History of The Church of Jesus Christ of Latter-day Saints. Hinckley wrote "What of the Mormons?" while he was employed as the Executive Secretary to the Church Radio, Publicity, and Mission Literature Committee. As part of the celebration of