From the Mineralogical Society of America: It is with extraordinary sadness that we report the passing of Gordon E. Brown, Jr., one of the most brilliant, prolific, and impactful mineralogists in the last half century. Gordon was the D.W. Kirby Professor Emeritus of Earth and Planetary Science at Stanford University, and Professor Emeritus of Photon Science, SLAC National Accelerator Laboratory. Gordon’s creation of and reach into at least a dozen specialties is almost unimaginable and essentially unmatched in his fields of study. He authored or co-authored over 400 publications attracting well over, to date, 52,000 citations and an H-index of 128 (Google Scholar). Gordon earned his PhD at Virginia Tech under the legendary Gerald V. Gibbs, and he was a Princeton professor before crossing over to Stanford in 1973. In his long career, he was awarded five major scientific medals, was made a Fellow of five scientific societies, and is a Past-President of MSA, as well as having served in a staggering number of service roles with a multitude of organizations around the world. There will be tributes to Gordon in the relatively near future, from memorials to conference sessions, all in his memory and honor. Please be watching for these.