| A | B |
|---|
| molten rock in the earth's mantle | magma |
| decaying plant and animal matter | humus |
| durable artificial rock | concrete |
| smells like mud when wet | shale |
| used to make chalkboards | slate |
| used in pencils instead of lead | graphite |
| person who studies minerals | mineralogist |
| hardest substance | diamond |
| look like mudball, but filled with crystals | geode |
| most useful metal | iron |
| rarest gemstone | ruby |
| only metal liquid at room temperature | mercury |
| best conductor of electricity | silver |
| most used conductor of electricity | copper |
| special kind of solid formed by all minerals | crystal |
| radioactive metal | uranium |
| lightweight, nonmagnetic, rustproof metal | aluminum |
| scientist who studies the structure of the earth | geologist |
| two types of weathering | chemical and physical |
| beautiful minerals not yet cut and polished | gemstones |
| cut and polished gemstones | gems |
| oil in its natural state | petroleum or crude |
| underground spring that shoots up boiling water from time to time | geyser |
| person who explores caves | spelunker |
| granite, pumice, obsidian | igneous |
| limestone, sandstone, shale | sedimentary |
| slate, marble | metamorphic |
| means "firey rock" | igneous |
| rock that floats | pumice |
| plant and animal remains turned to stone | petrified |
| National Park with many geysers and hot springs | Yellowstone National Park |
| fossils fomed when buried by mud | mold fossil |
| scientists who study fossils | paleontologists |
| outer portion of earth on which we live | crust |
| 5000 degrees F | mantle |
| 7000 degrees F | outer core |
| believed to be a ball of iron | inner core |
