==References==*Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., ISBN 0-471-80580-7*Boni, M., Gilg, H.A., Aversa, G., and Balassone, G., 2003, The "Calamine" of southwest Sardinia: Geology, mineralogy, and stable isotope geochemistry of supergene Zn mineralization: Economic Geology, v. 98, p. 731-748.
Callac (bretonsko Kallag) je naselje in občina v francoskem departmaju Côtes-d'Armor regije Bretanje.