Diopsidi

Diopsidi refers to a group of minerals characterized by their composition within the pyroxene family, specifically the orthopyroxene subgroup. The term originates from the mineral diopside (CaMgSi₂O₆), which serves as a prototypical example of this group. Diopsidi minerals are single-chain inosilicates, meaning their structure consists of linked silicon-oxygen tetrahedra forming continuous chains.

Diopside itself is a calcium magnesium silicate with a monoclinic crystal system, often appearing in green, yellow, or brown hues. It is commonly found in metamorphic and igneous rocks, including marbles, skarns, and basaltic lavas. Due to its stability and durability, diopside is occasionally used as a gemstone, though it is less common than other pyroxenes like enstatite or augite.

The broader diopsidi group includes solid solutions where magnesium (Mg) and iron (Fe) substitute for each other in the crystal structure, forming a series between diopside (Mg-endmember) and hedenbergite (Fe-endmember). This substitution is known as the diopside-hedenbergite series, reflecting gradual changes in chemical composition and physical properties.

Diopsidi minerals play a significant role in geological studies, particularly in understanding metamorphic processes and mantle compositions. Their presence in meteorites also provides insights into the mineralogy of extraterrestrial bodies. While not as widely recognized as some other silicate minerals, their structural and compositional diversity contributes to broader mineralogical and petrological research.