Rock, Definition, Characteristics, Formation, Cycle, Classification, Types, & Facts

Rock, in geology, naturally occurring and coherent aggregate of one or more minerals. Such aggregates constitute the basic unit of which the solid Earth is composed and typically form recognizable and mappable volumes. The three major classes of rock are igneous, sedimentary, and metamorphic rock.

4.3 Classification of Igneous Rocks – Principles of Earth Science

Igneous Rocks - Geology (U.S. National Park Service)

Types of Rocks

Shale Rock: Geology, Composition, Uses

Rock cycle - Understanding Global Change

Metamorphism - The Australian Museum

What are Sedimentary Rocks? - Types, Formation, Uses, Facts

How Many Types of Rocks are there ?

Introduction to Rocks — Earth@Home

Reading: Characteristics of Metamorphic Rocks

Exploring Rock Types: Igneous, Sedimentary, Metamorphic

Rock (geology) - Wikipedia