 He has served as a trustee of the Carnegie Institution of Washington since 1990.He was the 2004 recipient of the Penrose Medal of the Geological Society of America, 2006 recipient of the Roebling Medal of the Mineralogical Society of America, and 2008 recipient of the Marcus Milling Legendary Geoscientist Medal.Other honors include selection as a Fellow of the American Academy of Arts and Sciences and Member of the American Philosophical Society.