TL;DR: Spinel is a main entry in the 外星矿物知识引擎 database.
Spinel group minerals are found throughout lunar samples and meteorites. Chromite is a source of chromium for stainless steel production. Magnesiochromite spinel has been identified in specific lunar soil types as a potential ISRU feedstock.
Crystal System
Cubic (isometric)
Occurrence
Found in lunar highland regolith and mare basalts; present in chondritic meteorites
Significance
Source of chromium and magnesium; spinel-rich lunar soil identified as potential ISRU feedstock; high melting point useful for refractory applications
Source
Apollo samples, lunar orbital spectroscopy