Pyroxene

group of inosilicate minerals with single chains of silica tetrahedra

The pyroxenes are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. They share a common structure consisting of single chains of silica crystals with the general formula XY(Si,Al)2O6 where X and Y represents metal ions. Although aluminium substitutes extensively for silicon in silicates such as feldspars and amphiboles, the substitution occurs only to a limited extent in most pyroxenes.

A sample of pyroxenite, a rock consisting mostly of pyroxene minerals.
Pyroxene

Pyroxenite is an igneous rock made up of minerals from the pyroxene group.