| Magma | Molten Rock |
| Bedrock | solid, unmovable rock below the soil |
| Geode | hard, rocklike object which looks like a mudball and has cyrtals inside |
| Petroleum/Crude Oil | Oil in its natural state |
| Old Faithful | a famous geyser in Yellowstone National Park |
| Mold | a fossil formed when the mud that buries a plant or animal quickly hardens around it |
| Petrified Fossils | plant & animal remains that have turned to stone |
| Impurities | where quartz gets its color from |
| Uranium | a radioactive metal |
| Weathering | soil is formed by this process |
| Amber | the hardened sap of certain trees |
| Crystal | a solid that has a definite shape with flat surfaces and sharp edges |
| Extinct | no longer in existence |
| Gemstone | a rare, beautiful mineral that is very hard |
| Geologist | a scientist who studies the structure of the earth |
| Humus | decaying plant and animal material |