| Term | Definition |
| rock-forming mineral | a group of 20 minerals that make up most of the rocks in the earth's crust |
| granite | a henerally light-colored rock that has high silica content |
| basalt | a dark colored rock that is low in silica |
| grains | particles of minerals or other rocks |
| texture | the look and feel of a rock's surface |
| igneous rock | the type of rock that forms from the cooling of magma or lava |
| sedimentary rock | rock that forms when particles of other rocks or the remains of plants and animals are pressed and cemented together |
| metamorphic rock | the rock that forms when an existing rock is changed by heat, pressure, or chemical reactions |
| extrusive rock | igneous rock formed from lava that erupted onto earth's surface |
| intrusive rock | igneous rock that formed when magma hardened beneath earth's surface |
| foliated | the word describing the thin, flat layering found in most metamorphic rocks |
| sediment | small, solid pieces of material that come from rocks or living things |
| erosion | when running water, wind, or ice loosen and carry away fragments of rock |
| deposition | the process by which sediment settles out of the water or wind carrying it |
| compaction | the process that presses sediments together |
| cementation | the process in which dissolved minerals crystallize an glue particles of sediment together |
| clastic rock | a sedimentary rock that forms when rock fragments are squeezed together |
| organic rock | rock that forms where the remains of plants and animals areposited in thick layers |
| chemical rock | rock formed when minerals that are dissolved in a solution crystallize |
| rock cycle | a series of processes on earth's surface and in the crust and mantle that slowly change rocks frome one kind to another |