Ultramafic igneous rocks are composed almost entirely of __.
A) feldspar
B) quartz
C) ferromagnesian minerals
D) calcite
E) diamonds

Question

Quizplus · Accepted Answer

Ultramafic igneous rocks are composed almost entirely of ferromagnesian minerals such as olivine and pyroxene, which have high iron and magnesium content. They have very low silica content, unlike feldspar and quartz, and do not contain calcite or diamonds.

Ultramafic Igneous Rocks Are Composed Almost Entirely of __