More than half a century ago, Buzz Aldrin surveyed the lunar landscape, noted its starkness and ash-colored hues, and declared it a site of “magnificent desolation.” Extraterrestrial mineralogy is the study of minerals from our parental molecular cloud as well as from the Moon, Mars, asteroids, and similarly desolate places. The information gathered from detailed analyses of these phases has provided a deeper understanding of the myriad processes that can produce minerals in the Solar System and its erstwhile stellar neighborhood.