Glossary Crust: Rocky covering around the earth Crystal: A solid composed of atoms arranged in an orderly pattern Dirt: Mixture of crusted rock and pieces of organic material from plants and animals which covers some area of the crust Element: A substance such as iron, oxygen, and gold which cannot be separated or broken down by ordinary chemical methods Extrusive Rock: Igneous rock formed from lava that solidifies on are near the earth's surface Foliation: The bands of mineral crystals that occur in metamorphic rocks Fossils: Remains or evidence of a living thing Geode: A hollow rock in which crystals have formed inside the cavity Hardness: The amount of scratch resistance on a mineral's surface Igneous Rock: Rock formed from melted rock Intrusive Rock: Igneous rock formed when magma cools and solidifies beneath the earth's surface Lava: Melted magma from beneath the earth's crust which is forced up through cracks and pours forth from volcanoes Luster: The amount of light reflected from the surface of a mineral Magma: Molten rock beneath the earth's crust Mantle: Layer of the earth that extends from the bottom of the crust to the earth's core. Metamorphic Rock: Rock which is changed physically and sometimes chemically when subjected to heat and pressure Mineral: Substances which were never alive, made of one or more elements Rock Cycle: Gradual and continuous change of rock in the earth's crust to igneous, sedimentary, or metamorphic rock Sediments: Small pieces of rocks, shells, or the remains of plants and animals that have been carried along and deposited by wind, water, or ice. Sedimentary Rock: Crushed rock and organic material layered and compacted into new rock Volcano: An opening in the earth's crust that has released molten rock Weathering: The process during which rocks are broken up into smaller particles by the action of water, the atmosphere, and organisms |
