Built by a geologist
Rock ID Basics
Understand rock types, textures, and how to identify igneous, sedimentary, and metamorphic rocks. This free track includes 5 structured lessons with practical field context and review questions.
Lessons in Rock ID Basics
- The Rock Cycle — Understanding how rocks form and transform is essential for any geologist. The rock cycle describes the continuous process of rock formation, breakdown…
- Igneous Rock Classification — Igneous rocks are classified by their texture crystal size and composition mineral content . Mastering this classification system is essential for field…
- Sedimentary Rock Classification — Sedimentary rocks record Earth's surface history and often contain fossils, making them crucial for understanding past environments and finding…
- Metamorphic Rock Classification — Metamorphic rocks form when pre-existing rocks protoliths are transformed by heat, pressure, or chemically active fluids without melting.
- Rock ID in the Field — Putting it all together - practical strategies for identifying rocks in the field when perfect samples and laboratory equipment aren't available.
Verification resources
Cross-check terminology, classification, methods, and safety with these authoritative external resources.
- How rocks are classified — U.S. National Park Service. Rock-group classification using composition, texture, and geologic processes.
- Collecting rocks — U.S. Geological Survey. Field context, specimen observation, and responsible rock-collecting guidance.
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