John W. Judd (1840–1917) was a distinguished British geologist, mineralogist, and petrologist. He is primarily known for his extensive contributions to the understanding of volcanic geology, metamorphic rocks, and the geology of the British Isles.
Born in 1840, Judd pursued a career in geological science, becoming a prominent figure in the field during the late 19th and early 20th centuries. He served as Professor of Geology at the Royal School of Mines (which later became part of Imperial College London) from 1876 until his retirement in 1905, where he played a significant role in educating future generations of geologists.
His research interests were broad, encompassing the study of eruptive rocks, the origin and evolution of volcanoes, and the petrology of various rock types. He conducted detailed investigations into the geology of Scotland, particularly its ancient volcanic regions, and made significant contributions to the geological mapping and understanding of Leicestershire and other parts of England. Judd was also involved in the analysis of rock samples collected during the Challenger expedition, providing insights into the geology of deep-sea environments.
Judd was elected a Fellow of the Royal Society (FRS) in 1877, a testament to his scientific accomplishments. He was also awarded the prestigious Wollaston Medal by the Geological Society of London in 1891, its highest award, recognizing his outstanding contributions to geology. His notable publications include "Volcanoes: What They Are and What They Teach" (1881), a widely read and influential work that synthesized contemporary knowledge on volcanism.