Koesite is a high-pressure polymorph of silica (SiO2) that forms under extreme conditions, such as those found in impact craters or deep within the Earth's crust. It was first identified in the 1960s from materials associated with meteorite impacts. Koesite is characterized by its unique crystal structure, which differs from that of other silica forms like quartz and tridymite. Its study provides insights into geological processes and the conditions present during meteorite impacts.