HAÜY, RENÉ-JUST. - Priest, b. at St-Just (Oise) on 28 Feb. 1743, d. at Paris on 3 June 1822. An eminent crystallographer and mineralogist, he must be regarded as one of the founders of crystallography.
Educated at the Collège de Navarre, where he later became a professor, he there embraced the ecclesiastical career. He first occupied himself with the natural sciences in general and then, introduced by the mineralogist Daubenton, devoted himself entirely to mineralogy. From 1783 he was a member of the Academy of Sciences. In 1794 he was appointed curator of the Museum of Mines, and in 1802 he became professor of mineralogy at the Museum, where he succeeded Dolomieu. Finally, from its foundation he was professor of mineralogy at the University of Paris.
He owes his fame to the fundamental law of rational truncations, or rational indices, which he discovered and which derives its name from him, and to his theory of the structure of crystals, published in 1783 (v. CRISTALLO).
