Pyroxenite

Pyroxenite is an ultramafic igneous rock consisting essentially of minerals of the pyroxene group. Pyroxenites are classified into clinopyroxenites, orthopyroxenites, and the websterites which contain both types of pyroxenes.

This mineral essentially of igneous origin. Igneous pyroxenites closely allied to gabbros and norites and to peridotites. This connection indicated also by their mode of occurrence, for they usually accompany masses of gabbro and peridotite and seldom found by themselves.

Pyroxenite often very coarse-grained, containing individual crystals which may be several inches in length. The principal accessory minerals, in addition to olivine and feldspar, are chromite and other spinels, garnet, magnetite, rutile, and scapolite.