Igneous Rock Characteristics and Identification

This tutorial explains how to use the Ignus rock chart from the reference table to identify rocks. It covers the differences between extrusive and intrusive rocks, how to determine rock types based on crystal size, and the significance of vesicular and nonvesicular textures. The video also discusses rock characteristics such as color, density, and composition, providing a comprehensive guide to rock identification.

What is the primary purpose of the Ignus rock chart?

• To help identify igneous rocks

• To measure the density of rocks

• To identify sedimentary rocks

• To classify metamorphic rocks

How are extrusive rocks different from intrusive rocks?

• Intrusive rocks cool quickly

• Extrusive rocks have larger crystals

• Extrusive rocks form from volcanic eruptions

• Intrusive rocks are glassy

What determines the size of crystals in igneous rocks?

• The color of the rock

• The speed at which the rock cools

• The type of minerals present

• The location where the rock is found

Which tool is suggested for measuring crystal size in rocks?

• A ruler

• A thermometer

• A compass

• A magnifying glass

What texture indicates the presence of gas pockets in rocks?

• Fine

• Coarse

• Vesicular

• Glassy

What characteristic is used to determine the column of a rock on the chart?

• The rock's location

• The rock's weight

• The rock's age

• The rock's color and density

What does a light color in a rock typically indicate?

• The rock is mafic

• The rock is felsic

• The rock is intrusive

• The rock is extrusive

Which type of rock is associated with a lower density?

• Gabbro

• Diorite

• Basalt

• Granite

What happens when a granite plate collides with a basalt plate?

• The granite plate rides over the basalt plate

• The granite plate subducts

• The basalt plate rises

• Both plates remain stationary

Which side of the chart contains rocks with higher density?

• The top side

• The right side

• The bottom side

• The left side