Chapter 13, Problem 18E

Interpretation Introduction

Interpretation:

We know that intrusive igneous rock $\left(\text{granite}\right)$ has cooled slowly from magma. Rhyolite $\left(\text{Extrusive igneous rock}\right)$ has cooled very quickly. The intrusive rock has cooled slowly, at depth, where the overlying rocks have an insulating effect, but the extrusive rock has cooled quickly on the surface you know that granite is more crystalline than Rhyolite, it becomes clear that rate of cooling has a direct effect on the physical appearance of the rock.

Concept introduction:

Rate of cooling effect the amount of crystallisation. Slow cooling gives larger size of crystal but fast cooling gives smaller size of crystal. And very fast cooling gives amorphous solid.

To determine: the difference between $Si{O}_2$ that is cooled slowly and $Si{O}_2$ that is cooled quickly