| A | B |
|---|
| system | a group of parts that work together to form a whole |
| atmosphere | mixture of gases that surround and protect Earth |
| hydrosphere | all the water on Earth |
| biosphere | all life on Earth |
| geosphere | all the features on Earth's surface and below the surface |
| mineral | a substance that forms in nature, is a solid, has a definite chemical makeup, and has a crystal structure |
| element | a substance that contains only one type of atom |
| crystal | a solid substance in which the atoms are arranged in an orderly, repeating, three-dimensional pattern |
| streak | the color of the powder left behind when a mineral is scraped across a surface |
| luster | the way in which light reflects from a mineral's surface |
| cleavage | the tendency of a mineral to break along flat surfaces |
| fracture | the tendency of a mineral to break into irregular pieces |
| density | the amount of mass in a given volume of a substance |
| hardness | the resistance of a mineral or other material to being scratched |
| magma | molten rock beneath Earth's surface |
| lava | molten rock that has reached Earth's surface |
| ore | a rock that contains enough of a valuable mineral to be mined for a profit |
