His numerous papers and essays include Geologische Skizze van der Westkiisle Schottlands (1871); Die Struktur der Variolite (1875); Microscopical Petrography (in Report of U.S. Geol. Exploration of 4Oth Par., vol. vi., 1876); Limurit aus der Vallee de Lesponne (1879); Über den Zirkon (1880). His separate works include Lehrbuch der Petrographie (1866; 2nd ed. 1893, 1894); Die mikroskopische Beschaffenheit der Mineralien und Gesteine (1873).
Ferdinand Zirkel (March 20, 1838) - June 12, 1912) German geologist and petrographer, was born at Bonn. He was educated in his native town, and graduated Ph.D. at the university in 1861. In early years he was engaged in teaching geology and mineralogy in Vienna. He became professor of geology in 1863 in the university of Lemberg, in 1868 at Kiel, and in 1870 professor of mineralogy and geology in the university of Leipzig.