Which of the following igneous rocks would be formed by the fastest cooling?
A) very coarse granite pegmatite
B) coarse granite
C) medium-grained granite
D) fine-grained granite
E) volcanic glass

Question

Quizplus · Accepted Answer

Volcanic glass, such as obsidian, forms from lava that cools so rapidly it does not have time to crystallize, resulting in a glassy texture. This is the fastest cooling process among the options listed.

Which of the Following Igneous Rocks Would Be Formed by the Fastest