Igneous Rock Pre-Test

Extrusive rocks are formed

• underwater

• in a lab

• deep underground

• above the surface of a volcano

The most common INTRUSIVE igneous rock is

• granite

• gabbro

• rhyolite

• sandstone

The SLOWER magma cools, the SMALLER the mineral crystals form.

• True

• False

Rocks that are formed from magma or lava are called

• sedimentary

• metamorphic

• igneous

• clastic

This EXTRUSIVE igneous rock is

• obsidian

• basalt

• pumice

• granite

A common characteristic that could help you identify an igneous rock as cooling on the surface (EXTRUSIVE) is...

• Vesicles (air bubbles) and very large crystals

• Vesicles (air bubbles) and very small or no crystals

• Large crystals and multi-colored

• Being dark or light in color and having layers

The size of crystals in an Igneous Rock depends upon

• pressure

• the presence of air

• the presence of water

• cooling rate (fast vs. slow)

An igneous rock that is formed from LAVA (OUTSIDE of the volcano) is called...

• Extrusive

• Intrusive

Coarse-grained intrusive igneous rocks with large crystals (like granite) result when

• Sedimentary rocks are cemented and compacted.

• magma cools quickly

• magma cools slowly

• lava cools quickly

This EXTRUSIVE igneous rock is

• granite

• basalt

• obsidian

• pumice