Lunar Sample Number 79155,10. Retrieved during Apollo 17’s Moon walks, December 7-19, 1972.

Loan courtesy of NASA.

This artifact is from the Moon’s Taurus-Littrow Valley site. The mineral formed when molten magma cooled to a crystal structure. Rocks help explain the Moon’s age, encounters with meteors and geological composition. They are often three to four billion years old - much older than most Earth rocks.