Igneous Rocks Lesson

Igneous Rocks

Vocabulary Review

• Mineral: natural, solid substance that has a definite chemical composition and physical structure

• Magma: melted rock within the earth

• Igneous Rock: forms when magma is pushed up from the mantle into the cool crust and hardens into rock

• Lava: Magma that reaches the surface

Multiple Choice

Where is lava located?

• above ground

• below ground

• in the core

• in the mantle

Multiple Choice

Where is magma located?

• above ground

• below ground

• in the stratosphere

• in the thermosphere

Multiple Choice

Igneous rock that forms when magma hardens beneath Earth's surface

• Intrusive Rock
• Compaction
• Extrusive Rock

Multiple Choice

Igneous rock that forms from lava on Earth's surface

• Organic Rock
• Intrusive Rock
• Extrusive Rock

Fill in the Blanks

Which type of igneous rock would be easier to mine?

Obsidian is an example of an extrusive rock. Because it cooled and hardened quickly, extrusive rocks have a fine grained texture.

Granite is an intrusive igneous rock. Because they cool slowly, the crystals are large giving these rocks a coarse texture.

Multiple Choice

Diorite is an intrusive igneous rock. What does this tell you about it?

• it was formed from lava that erupted onto Earth's surface

• it was formed from magma that hardened beneath Earth's surface

• it was formed from rapidly cooling lava

Multiple Choice

Basalt is an extrusive igneous rock. What does this tell you about it?

• it was formed from lava that erupted onto Earth's surface

• it was formed from slowly cooling magma

• it was formed from magma that hardened beneath Earth's surface

Multiple Choice

Pegmatite is a coarse-grained, intrusive, igneous rock. How did it form?

• rapidly cooling lava

• slowly cooling magma

Multiple Choice

Rhyolite is a fine-grained, extrusive, igneous rock. How did it form?

• rapidly cooling lava

• slowly cooling magma

Multiple Choice

Is this igneous rock, obsidian, fine-grained or coarse-grained?

• fine-grained

• coarse-grained

Multiple Choice

Is this igneous rock, porphyry, fine-grained or coarse-grained?

• fine-grained

• coarse-grained

Multiple Choice

What option below is NOT one of the uses of igneous rocks?

• statues

• kitchen counters

• building materials

• chalkboards