Some minerals are extremely soft--as soft as baby powder. Other minerals are extremely hard--like diamonds, the hardest natural substance in the world. Some rocks were once extremely hot--they were made from magma deep under the earth. Do you know that you use minerals when you look in a mirror, brush your teeth, or sprinkle salt on your French fries? Find out all the answers about rocks and minerals--even how to study them yourself--when you dig in to "Extreme Rocks #38; Minerals! Q #38; A, " Gr 3 6 It's hard to beat this title for a clear, accurate, and appealing survey. Illustrations are key to this subject, and the range of crisp photos is excellent. From large landscapes like the surface of Mars and a sunset view of the Taj Mahal to close-ups of the Carmen Lúcia ruby and the pebbles in a piece of breccia, each image is carefully placed to add meaning. Beginning with the definitions of rocks and minerals, the well-organized text goes on to describe igneous, sedimentary, and metamorphic rocks and gemstones, explaining how each one is identified and used and where it is found on Earth. A spread at the end introduces a geologist who tells about her work and gives advice to aspiring scientists. Internet links throughout the text send readers to multimedia pages on the Smithsonian's site that correspond to topics addressed. Additional links in the "More to See and Read" section include Harvard's Mineralogical Museum and the American Museum of Natural History. Although it is not clear what makes these rocks and minerals "extreme, " they are certainly eye-catching. This is not the first or only book of its type, but the quality of text and illustrations makes it a standout.