Pyroxene
Appearance
![](http://upload.wikimedia.org/wikipedia/commons/thumb/9/9e/Orthopyroxenite_%28ALH84001%29.gif/220px-Orthopyroxenite_%28ALH84001%29.gif)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/7/74/Diopside-172005.jpg/220px-Diopside-172005.jpg)
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.
Pyroxenite is an igneous rock made up of minerals from the pyroxene group.