Scientists first suspected the existence of the mineral "hapkeite" on the moon 30 years ago. Researchers have now confirmed the suspicion after finding the mineral on a meteorite which crashed to earth from the moon in 2000.
The meteorite Dhofar 280 was investigated and the findings reported in the Proceedings of the National Academy of Sciences. Hapkeite results from so called "space weathering", and has a ratio of 2 parts iron to 1 part silicon.
"Space Weathering" occurs when the impact of micro-meteorites crush surface rocks on a very small scale. Micro-meteorites are approximately 0.1mm or less in diameter, but travel at speeds of about 100,000km/h. Source