Lesson 2

STUDY
PLAY
rock forming mineral
20 minerals make up most of Earth's crust.
granite
generally a light colored rock that has high silica content.
basalt
dark colored rock that has lower silica content.
grain
particles of minerals or other rocks.
texture
the look and feel of a rock's surface.
igneous rock
forms from the cooling of magma or lava.
sedimentary rock
forms when small particles of rock or plant and animal remains are squeezed together below the surface.
metamorphic rock
forms when a rock is changed by heat, pressure, or chemical reactions deep underground.