| A | B |
|---|
| rock | natural, solid, nonliving, material made of one or more minerals |
| mineral | a natural material that forms from nonliving matter |
| igneous rock | rock that forms when melted earth materials cool and harden |
| sedimentary rock | rock that forms when small pieces of earth materials collect and become bound together |
| metamorphic rock | rock that forms when existing rock is changed by heat and pressure |
| soil | the part of Earth's surface consisting of humus and weathered rock in which plants grow |
| decay | to break down or rot |
| nutrient | thing plants need in order to grow |
| loam | soil that contains a mixture of humus and mineral materials of sand, silt, and clay |
| humus | dark material found in soil that is made up of decaying plants and animals |
| the best ways to identify minerals | hardness and streak |
| halite | salt |
| fluorite | toothpaste |
| iron | legs on a desk |
| calcium | strong bones and teeth |
