The chemistry and mineralogy of the LX high-fidelity lunar regolith simulants

To support sustainable solar system exploration, humans must harness resources from celestial bodies like the Moon to build infrastructure and obtain essential consumables, including water and oxygen. Lunar regolith, a loose rock layer covering the Moon’s surface, is a key resource for in-situ resource utilisation (ISRU) technologies. Developing and testing these technologies on Earth relies on the use of accurate simulant materials. In prior studies, the LX lunar regolith simulant system was developed and the base simulants LX-T100 (anorthosite) and LX-M100 (basalt) were thoroughly characterised in terms of their bulk mineralogical and bulk chemical composition, particle size distribution, particle morphology, density, void ratio and porosity, adsorption and BET-specific surface area, compressibility, flow, magnetic and optical properties. This work focuses on the LX high-fidelity simulants, specifically their mineralogy and chemistry. The high-fidelity simulants are composed of four source rocks, namely the anorthosite of LX-T100, the basalt of LX-M100, as well as a harzburgite as a source for olivine and pyroxene and an ilmenite ore as a source for ilmenite. The bulk mineralogy and chemistry of the harzburgite and ilmenite ore, as well as the crystal chemistry of all four source rocks, were analysed and the results were compared with the lunar samples from the Apollo and Luna missions. Finally, a deviation analysis was carried out in which the bulk chemistry of the LX high-fidelity simulants and 13 other relevant simulants from research and industry were compared with the chemical composition of the lunar soil at the landing sites of the Apollo, Luna and Chang’e 5 missions. It was shown that of all simulants, the LX high-fidelity simulants can on average best mimic the chemical composition of the lunar soil. The findings from these investigations deepen the understanding of the LX lunar regolith simulants, increasing their reliability for scientific research. • First characterisation of the mineralogy and chemistry of the LX high-fidelity simulants provided. • Simulant properties show good agreement with lunar mineralogy and chemistry. • LX high-fidelity simulants mimic lunar soil chemistry better than most available simulants. • LX high-fidelity simulants best mimic Apollo 11, 12, 17,Luna 16, 20 soil chemistry.