Some rocks are made up of materials from living things.

Some rocks take millions of years to form.

All rocks are made up of the same kinds of minerals.

Some rocks form from particles of other rocks.

A combination of one or more minerals or organic matter is called _.

The three classes of rock are _, _, and _. (choose three)

The minerals and organic matter a rock contains determine the _, or makeup, of that rock.

The size, shape, and positions of the grains that make up a rock determine the rock's _.

When magma pushes into, or intrudes, surrounding rock below Earth's surface and cools, the rock that forms is called _.

Examples of intrusive igneous rock are _ and _.

Igneous rock that forms when lava erupts, or extrudes, onto Earth's surface is called _.

_ is an extrusive rock that cools so rapidly that no crystals form.

Obsidian looks glassy, so it is often called _.

Other common extrusive igneous rocks are _ and _.

Sometimes lava erupts and flows from long cracks in Earth's crust called _.

Processes that form _ rock are weathering, erosion, deposition, burial, and cementation.

_ and _ are coarse-grained clastic sedimentary rocks.

_ sedimentary rock forms when sediments are buried, compacted, and cemented together by calcite or quartz. _ sedimentary rocks form when water, usually seawater, evaporates.

Animal remains, together with sediment, are eventually buried, compacted, and cemented together to form _ limestone.

_ is a fossiliferous limestone that consists of the shells of marine mollusks that have been cemented together by calcite.

Two types of organic sedimentary rock are _ and _.

_ forms from the remains of fossils, or once-living plants and animals.

_ forms when sodium ions and chlorine ions in shallow bodies of water become so concentrated that _ crystallizes from solution.