Chapter 3.2 Classifying Rocks

Select the THREE characteristics that geologists use to classify rock samples.

• Rock color and mineral composition
• Rock origin
• Rock Texture
• Streak
• Luster

______________ is a dark colored rock with a low silica content

• Basalt
• Granite

The look and feel of a rock's surface is its....

• Color
• Texture
• Composition
• Origin

When the grains are large enough to see without a microscope, the texture is called...

• Banded
• Coarse grained
• Fine Grained
• Non-banded

The particles of minerals or other rocks that make up a rock are called....

• Elements
• Grains
• Crystals

The 20 minerals that make up most of the rocks of Earth's crust are called....

• Rock-Forming minerals
• Igneous
• Silicates

_______________ is a generally light colored rock with a high silica content

• Basalt
• Granite

_____________ rock forms when rock particles get pressed and cemented together.

• Igneous
• Sedimentary
• Metamorphic

_____________ rock forms when rock is changed by heat or pressure.

• Igneous
• Sedimentary
• Metamorphic

_____________ rock forms when magma or lava cools and then hardens.

• Igneous rocks
• Sedimentary
• Metamorphic