| Front | Back | 
| 
								Igneous									 | 
								Formed from the hardening of molten rock, magma, lava. Ex: granite, pumice, basalt, obsidian. | 
| 
								Sedimentary									 | 
								Formed by sedimentation, gradual depositing or small bits of rock or clay. FOSSILS. Shale, sandstone, gypsum, dolomite, coal. 									 | 
| 
								Metamorphic									 | 
								Formed when existing rock material is altered through temperature, pressure, or chemical process. Ex: marble, slate, gneiss, quartzite. 									 | 
| 
								Age of Earth									 | 
								4.6 billion years old									 | 
| 
								Precambrian Eon									 | 
								4.6 billion years ago - 570 million years ago. Before the fossil record began.									 | 
| 
								Life on Earth									 | 
								3.5 billion years ago									 |