Sinoite

Sinoite is a rare silicate mineral with the chemical formula CaMgSi₂O₆. It is the calcium-magnesium endmember of the pyroxene group.

Occurrence: Sinoite is primarily found in meteorites, particularly enstatite chondrites and aubrites. Its presence is indicative of highly reduced conditions during the formation of the meteorite parent body. It is often associated with other rare minerals like niningerite, oldhamite, and perryite.

Properties: Sinoite is typically a light-colored mineral, ranging from colorless to white or pale gray. It is characterized by its orthorhombic crystal structure. Its hardness and density are within the typical ranges for pyroxene minerals. Due to its rarity and small grain size, its physical properties are not as well-studied as those of more common pyroxenes.

Significance: The presence of sinoite in meteorites provides valuable insights into the conditions prevailing in the early solar system and the processes involved in the formation of asteroids and other planetary bodies. Its reduced mineralogy is indicative of an oxygen-poor environment. The study of sinoite can help to understand the distribution of elements and the evolution of the solar nebula.