Via Science:

A mineral previously known only from moon rocks and lunar meteorites has now been found on Earth. Researchers discovered the substance—dubbed tranquillityite after the Sea of Tranquility, where Apollo 11 astronauts landed on the Moon in July 1969— at six sites in Western Australia. The mineral occurs only in minuscule amounts and has no economic value, but scientists say it could be used for age-dating the rocks in which it occurs.

Photograph: “This Moon Rock, from Apollo 14, visited three classes at Wadena-Deer Creek, a K-12 school in Minnesota, where Debra’s brother David teaches. Credit: NASA/Sean Smith