The site, presented by About.com, categorizes and lists a plethora of different rocks. They have divided them by their rock structure: igneous, sedimentary, and metamorphic. Under each category are a list of different...

If you are having difficulty remembering the details of the Earth's geological structure or the nature of major minerals and rock types, you can consult this excellent introductory course offered as part of MIT's...

This interactive lesson on metamorphic rocks starts with a review of the rock cycle and goes on to describe the relationship between metamorphic rocks and their parent rock. The lesson then describes the agents of...

This site features Flash animations that illustrate various facets of the rock cycle. The visualizations depict rock-forming processes, such as erosion, transportation, deposition, cementation, crystallization,...

This guide provides illustrated descriptions of 46 common and important varieties of igneous, sedimentary, and metamorphic rock found in the San Francisco Bay region. Rock types are described in context of their...