- sedimentary
- sediments (gravel, sand, silt, clay)
- volcano
- magma
- igneous
- melting/cooling/hardening
- metamorphic
- weathering/erosion
- wind, rain, water
- pressure and heat
- lava
- marble, quartz = metamorphic
- fossils
- limestone, conglomerate = sedimentary
- basalt, obsidian = igenous
- rock layers (sedimentary --> metamorphic)