Hapkeite is a mineral discovered in the Dhofar 280 meteorite found in 2000 in Oman on the Arabian peninsula. The meteorite is interpreted to originate from the Moon, specifically it appears to be a fragment of lunar highland breccia. Hapkeite's composition is of silicon and iron, and is similar to other silicon-iron minerals found on Earth. On the Moon an impact is thought to have launched the partially molten or vaporized material into orbit.

Due to its 1:2 composition of silicon-iron, hapkeite was given the chemical formula Fe2Si. It occurs as opaque, yellowish to silvery microscopic isometric crystals.

It is named after University of Pittsburgh scientist Bruce Hapke, who predicted the presence and importance of vapor-deposited coatings on lunar soil grains about 30 years ago.