George Davis Louderback (April 6, 1874 – January 27, 1957) was an American geologist, known for identifying and describing benitoite and joaquinite.
[3] He was a teaching assistant in mineralogy at UC Berkeley in 1897–1900 and then taught at the University of Nevada in 1900–1906.
In Nevada, Louderback studied the geological structure of the Great Basin, especially of the Basin ranges, and Nevada's gypsum deposits.
He did research on the Mesozoic formations of southern Oregon, the relation of radioactivity to vulcanism, the glaucophane of the Pacific Coast Ranges, and the stratigraphy of Mount Diablo.
In 1914–1916 Louderback led an expedition searching for petroleum reservoirs in the interior of China; after the expedition, in 1916 he also searched for petroleum in the Philippine Islands.