Understanding What Igneous Rock Is
Igneous rock is a type of rock formed when molten magma or lava cools and hardens. These rocks are directly linked to volcanic and deep Earth activity.
How Igneous Rock Forms
When magma cools slowly underground, it forms intrusive igneous rocks with large crystals. When lava cools quickly on the surface, it forms extrusive rocks with small crystals.
Types of Igneous Rock
Granite is an intrusive rock with large minerals.
Basalt is an extrusive rock formed from fast-cooling lava.
Obsidian cools so quickly it forms natural volcanic glass.
Where Igneous Rocks Are Found
They appear near volcanoes, in old lava flows, beneath Earth’s crust, and in regions with past volcanic activity. They form the base of many continents and oceans.
Why Igneous Rocks Matter
These rocks reveal clues about Earth’s internal heat, volcanic eruptions, and the minerals that make up the crust. They are also used in construction and tools.
How Igneous Rocks Change
With erosion, melting, or pressure, igneous rocks become part of the rock cycle. They can transform into sedimentary or metamorphic rocks over time.
The Simple Takeaway
Igneous rock forms when molten material cools and solidifies. It captures Earth’s volcanic history and plays a key role in the planet’s geology.