Orthopyroxenite
Orthopyroxenite is an ultramafic igneous rock composed of over 90% orthopyroxene. Orthopyroxenes are a group of minerals that form a solid solution series between enstatite (MgSiO3) and ferrosilite (FeSiO3). Consequently, orthopyroxenite can range in composition from magnesium-rich to iron-rich. These rocks are typically coarse-grained and can appear dark green, brown, or black depending on the iron content of the pyroxene.
Orthopyroxenites are found in various geological settings. They are common in the Earth's upper mantle, forming
The formation of orthopyroxenite is typically associated with fractional crystallization processes. As magma cools, minerals crystallize