An ultramafic plutonic rock composed chiefly of pyroxene.

A rock composed almost entirely of pyroxene.

An ultramafic intrusive rock, chiefly composed of the mineral pyroxene

a rock composed in large part, of pyroxene. It is an ultramafic igneous rock. [AHDOS

Pyroxenite is an ultramafic igneous rock consisting essentially of minerals of the pyroxene group, such as augite and diopside, hypersthene, bronzite or enstatite. They are classified (see diagram below) into clinopyroxenites, orthopyroxenites, and the websterites which contain both pyroxenes. Closely allied to this group are the hornblendites, consisting essentially of hornblende and other amphiboles.