ortopyrokseeneja

Ortopyrokseeneja is the plural form in Finnish for orthopyroxene. Orthopyroxenes are a group of silicate minerals that belong to the pyroxene group. They are characterized by their orthorhombic crystal structure and their chemical composition, which is generally represented by the formula (Mg,Fe)2Si2O6. This formula indicates that the primary cations present are magnesium (Mg) and iron (Fe), along with silicon (Si) and oxygen (O).

The specific composition of an orthopyroxene can vary significantly, leading to a continuous solid solution series. The end-members of this series are enstatite (Mg2Si2O6) and ferrosilite (Fe2Si2O6). Intermediate compositions are named based on their relative proportions of magnesium and iron. For example, bronzite and hypersthene are terms historically used for orthopyroxenes with intermediate amounts of iron.

Orthopyroxenes are important rock-forming minerals found in a variety of igneous and metamorphic rocks. They are particularly abundant in mafic and ultramafic igneous rocks such as basalt, gabbro, and peridotite. In metamorphic rocks, orthopyroxenes can form under conditions of high temperature and pressure, often found in granulite-facies rocks. Their presence and composition can provide valuable information about the geological conditions under which the rocks formed.