Rare earth mineral reidite found in impact crater in Wisconsin.

http://phys.org/news/2015-01-rare-mineral-wisconsin-crater.html

The rare earth mineral reidite was found in an impact crater in Wisconsin.  It is referred to as the Rock Elm meteorite. 

Reidite is created at high pressures and was first identified in the laboratory in the 1960s. The conditions in which reidite forms have been well-constrained by experiments in the lab but, prior to Rock Elm, it was only found naturally in the Chesapeake Bay Impact Structure (Virginia), the Ries Crater (Germany), and the Xiuyan Crater (China).

Read more at: http://phys.org/news/2015-01-rare-mineral-wisconsin-crater.html#jCp