A very hard, non-foliated metamorphic rock composed microscopically small crystals is classified as a(n)
A) amphibolite.
B) greenstone.
C) slate.
D) hornfels.

Question

Quizplus · Accepted Answer

Hornfels is a very hard, non-foliated metamorphic rock composed of microscopically small crystals that form due to intense heat and pressure. Amphibolite is a foliated metamorphic rock composed of larger crystals, greenstone is a term used to describe a variety of green-colored igneous or metamorphic rocks, and slate is a foliated metamorphic rock composed of very fine-grained minerals.

A Very Hard, Non-Foliated Metamorphic Rock Composed Microscopically Small Crystals