Lesson 5 The Cycling of Earth’s Materials – Max learned what happens to rocks at Earth’s surface. Then he learned that sediment deposited in water often forms layers in the beds of rivers, lakes, and oceans. Over time these layers can be preserved in sedimentary rocks. Next he learned that lithification is the process through which sediment turns into rock. Then he learned that cementation is the process by which minerals dissolved in surrounding water crystallize between grains of sediment such as quartz, calcite, and Clay. Next we looked at several samples of sedimentary, metamorphic, and igneous rocks. He was given a geode to open with a hammer to determine what type of rock it contained.