THIS book is intended for two classes of reader, namely, the student beginning the study of the igneous rocks, and the geologist seeking a refresher course. As a result, the beginner will need ...

Sedimentary rocks give a geologic history lesson with their layers. For example: sand made from quartz forms into sandstone; clay minerals compress into shale. Igneous rocks are made from once hot ...

Igneous rocks close igneous ... it will form extrusive rock, e.g. basalt. These rocks are formed when magma solidifies. As the magma cools, mineral crystals will begin to grow.