It’s been more than 50 years since the Apollo missions, and in that time, chemical analyses of the recovered lunar materials have revolutionized our understanding of planetary materials. One of the major findings as a result of this research is the recognition that the moon is exceptionally depleted in particular volatile elements, and that these moon rocks also exhibit large chemical anomalies unlike anything seen on Earth.
Source:
https://phys.org/news/2020-09-nasa-scientists-depletion-halogens-due.html