| A | B |
|---|
| how well a mineral resists scratching | hardness |
| a resource that can be replaced in a short period of time | renewable |
| a layer of gas in the atmosphere that screens out much of the sun's UV rays | ozone layer |
| getting fresh water from seawater | desalination |
| Earth's internal energy | geothermal |
| wter seeps into the ground into spaces between bits of rock and soil | groundwater |
| storage for freshwater | reservoir |
| renewable energy we get from plant matter and animal wastes | biomass |
| remains or imprint of living things of the past | fossil |
| mixture of smoke and fog | smog |
| rock formed under heat and pressure, resulting in a different rock | metamorphic rock |
| rock formed when melted rock material cools | igneous rock |
| rock formed by small bits of matter joined together | sedimentary rock |
| solid material of Earth's crust with a definite composition | mineral |
| the way light bounces off a mineral's surface | luster |
| color of the powder left when a mineral is rubbed against a hard, rough surface | streak |
| the tendency of a mineral to break along flat surfaces | cleavage |
| a mineral containing a useful substance | ore |
| a mineral valued for being rare and beautiful | gem |
| a resource that cannot be replaced within a short period of time or at all | nonrenewable resource |
| naturally formed solid in the crust, made of one ore more minerals | rock |
| decyed plant or animal material in the soil | humus |
| rocks changing from one form into another in a never-ending series of processes | rock cycle |
| a fuel formed from the decay of ancient forms of life | fossil fuel |
| moisture that falls into Earth after being mixed with wastes from burned fossil fuels | acid rain |
| an underground layer of rock or soil filled with water | aquifer |
| a hole dug below the water table that water seeps into | well |
| a place where groundwater seeps out of the ground | spring |
| the top of the water-filled spaces in the ground | water table |
