Igneous, Sedimentary, Metamorphic: Types of Rocks Quiz

If the rock cycle is a continuous, circular process, then matter is constantly being recycled. If any rock type can turn into any other rock type, then there is no definitive start or end.

If molten rock reaches the surface, then it is called lava. If lava cools quickly in the open air or water, then it forms extrusive igneous rock.

If we classify rocks by how they form, then the three scientific categories are igneous (cooling), sedimentary (layering), and metamorphic (heat/pressure).

If sandstone is a sedimentary rock and it gets buried deep underground, then it is exposed to heat and pressure. If these forces recrystallize the quartz grains, then it becomes the metamorphic rock quartzite.

If rock material is in a molten state (magma or lava), then it must lose heat to become solid. If it cools and crystallizes, then the resulting rock is classified as igneous.

If an existing rock is subjected to high heat and crushing pressure without melting, then its mineral structure changes. If the minerals reorganize into a new form, then it is a metamorphic rock.

If magma is located deep underground, then it is insulated by the surrounding crust. If it stays trapped there and cools slowly, then it forms intrusive igneous rock.

If fossils are preserved in layers of sand or mud, then they must be in sedimentary rock. If igneous or metamorphic rocks involve melting or intense heat, then the fossils would be destroyed.

If a metamorphic rock is squeezed from specific directions, then the minerals align in parallel rows. If this alignment creates a striped or layered appearance, then it is called foliation.

If physical or chemical forces act on a rock surface, then the rock will crack and crumble. If the rock breaks into small fragments, then this specific process is defined as weathering.

If layers of sediment pile up, then the weight squeezes the bottom layers (compaction). If minerals act like glue to bond the pieces together, then it is called cementation, resulting in sedimentary rock.

If wind, water, or ice carries weathered rock fragments away, then the material is in motion. If sediment is being transported to a new place, then the process is known as erosion.

If any rock is pushed deep enough into the Earth's mantle, then temperatures become high enough to melt it. If it melts, then it becomes magma, regardless of its original type.

If the rock is melted and remains underground, then it is magma. If it breaks through to the surface, it becomes lava; therefore, the underground form is magma.

If the moving medium (water or wind) slows down, then it can no longer carry the weight of the sediment. If the sediment drops to the bottom, then the process is deposition.

If the molten rock is underground, then we call it magma. If it reaches the surface, then we call it lava. If the only change is where it is found, then the difference is location.

If lava cools almost instantly on the surface, then crystals cannot grow, resulting in a glassy rock. If obsidian is a volcanic glass formed on the surface, then it is extrusive igneous.

If an igneous rock is buried but does not melt, then it can be changed by heat. If it is also squeezed by the weight of the crust, then the pressure will transform it into metamorphic rock.

If a rock is made of compressed sand, it is sandstone. If it is made of mud/clay, it is shale. If it is made of shells/calcite, it is limestone. If these are formed from layers, then they are sedimentary.

If a rock like coal forms from dead swamp plants, then it comes from living matter. If it comes from living matter, then it is classified as an organic sedimentary rock.