Brownleeite

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Brownleeite is a rare manganese silicide mineral with the chemical formula MnSi. It forms tiny cubic grains and was found by NASA scientists at the Johnson Space Center while studying dust from the Pi Puppid shower of comet 26P/Grigg-Skjellerup. The only other known natural manganese silicide is mavlyanovite (Mn5Si3). The grains were collected from the Earth's stratosphere over the southwestern United States in April 2003 using a NASA ER-2 aircraft, and the team from the US, Germany, and Japan was led by Keiko Nakamura-Messenger. In 2005, a new transmission electron microscope was installed at JSC to study its origin and other dust materials. The mineral was officially named Brownleeite by the International Mineralogical Association in 2008 (IMA 2008-011), in honor of Donald E. Brownlee, a University of Washington astronomy professor known for his work on interplanetary dust particles.