In this Grade 6 Earth Science lesson from Chapter 3: Rocks, students learn that most rocks are composed of one or more minerals and explore the key differences between rocks and minerals in terms of structure and composition. Students identify the three main rock types — igneous, sedimentary, and metamorphic — and explain how the rock cycle describes the processes by which one rock type can transform into another. The lesson also covers how common each rock type is within Earth's crust.
Section 1
Minerals Combine to Form Rocks
Most rocks contain one or more minerals that combine in various proportions. While minerals have orderly crystal structures and consistent compositions, rocks can vary in their mineral content and arrangement.
Section 2
Rocks Transform Through the Rock Cycle
The rock cycle continuously changes rocks from one type to another through natural processes. Though rocks appear unchanging, they transform over thousands or millions of years through melting, weathering, and pressure.
Section 3
Scientists Classify Rocks into Three Types
Geologists organize rocks as igneous (formed from cooling molten material), sedimentary (pressed from fragments of other materials), or metamorphic (transformed by heat and pressure from existing rocks).
Section 4
Earth's Crust Distributes Rock Types Unevenly
Igneous and metamorphic rocks make up 95% of Earth's crust, while sedimentary rocks form only a thin 5% surface layer. This distribution reflects where and how the different rock types form.
Section 5
Meteorites Deliver Space Rocks to Earth
About 30,000 rocks from space land on Earth yearly. These meteorites mostly fall unnoticed in oceans or unpopulated areas, but larger impacts can create craters and permanently alter minerals through their tremendous energy.
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Section 1
Minerals Combine to Form Rocks
Most rocks contain one or more minerals that combine in various proportions. While minerals have orderly crystal structures and consistent compositions, rocks can vary in their mineral content and arrangement.
Section 2
Rocks Transform Through the Rock Cycle
The rock cycle continuously changes rocks from one type to another through natural processes. Though rocks appear unchanging, they transform over thousands or millions of years through melting, weathering, and pressure.
Section 3
Scientists Classify Rocks into Three Types
Geologists organize rocks as igneous (formed from cooling molten material), sedimentary (pressed from fragments of other materials), or metamorphic (transformed by heat and pressure from existing rocks).
Section 4
Earth's Crust Distributes Rock Types Unevenly
Igneous and metamorphic rocks make up 95% of Earth's crust, while sedimentary rocks form only a thin 5% surface layer. This distribution reflects where and how the different rock types form.
Section 5
Meteorites Deliver Space Rocks to Earth
About 30,000 rocks from space land on Earth yearly. These meteorites mostly fall unnoticed in oceans or unpopulated areas, but larger impacts can create craters and permanently alter minerals through their tremendous energy.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter