George Robert Rossman, a distinguished American mineralogist and Professor of Mineralogy, emeritus, at the California Institute of Technology (Caltech), passed away on February 6, 2026, at the age of 81. His passing marks the end of a prolific career dedicated to understanding the intricate compositions and spectroscopic properties of minerals. Rossman's pioneering research significantly advanced the fields of mineralogy, gemology, and inorganic chemistry, leaving an indelible mark on scientific understanding.

Born on August 3, 1944, in La Crosse, Wisconsin, Rossman cultivated an early passion for the natural sciences, collecting minerals and building a home chemistry laboratory. He graduated as salutatorian from his high school in Eau Claire in 1962. He continued his academic journey at Wisconsin State University–Eau Claire, earning a Bachelor of Science degree in both Chemistry and Mathematics in 1966, graduating summa cum laude with honors in Chemistry.

Rossman pursued his doctoral studies at Caltech, where he earned a PhD in inorganic chemistry in 1971. Immediately following his graduation, he joined the Caltech faculty, beginning a long and impactful tenure that saw him rise to Professor of Mineralogy. His research at Caltech focused on mineral spectroscopy, particularly the study of trace hydrous components in nominally anhydrous minerals, the origin of color in minerals and gems, and the effects of natural radiation.

Throughout his career, Professor Rossman was a prolific author, contributing to over 380 articles in his specialized fields. His profound contributions were recognized with numerous accolades, including the inaugural Dana Medal in 2001 and the prestigious Roebling Medal in 2021, both from the Mineralogical Society of America. His excellence in teaching was also celebrated with the Richard P. Feynman Prize for Excellence in Teaching from Caltech in 2004.

Rossman's legacy is further cemented by the naming of three mineral species in the tourmaline family after him: rossmanite in 1998, alumino-oxy-rossmanite in 2020, and fluor-rossmanite in 2024. These honors underscore his fundamental and lasting impact on mineralogical nomenclature and research. His dedication to both discovery and education inspired generations of students and colleagues, ensuring his influence will continue to resonate within the scientific community.