Mineral Nomenclature: Zirconolite

Peter Bayliss, Fiorenzo Mazzi, Rosalba Munno and Tim J. White
Department of Geology and Geophysics, The University of Calgary, Alberta, Canada T2N 1N4
Dipartimento di Scienze della Terra—Sezione di Mineralogia, Petrografia e Geochimica—Via A. Bassi, 4—Pavia, Italy
Dipartimento di Geofisica e Vulcanologia—Largo San Marcellino, 10—Naples, Italy
University of Melbourne, School of Physics, Parkville, Victoria, Australia 3052

Abstract: The nomenclature of CaZrTi2O7 minerals has become very confused, such that zirconolite, zirkelite and polymignite each have acquired multiple meanings and represent five different crystal structures. To resolve these inconsistencies, the IMA approved resolutions as follows. Zirconolite is the non- crystalline (metamict) mineral or mineral with undetermined polytypoid of CaZrTi2O7. Zirconolite-3O is the three-layered orthorhombic polytypoid of CaZrTi2O7. Zirconolite-3T is the three-layered trigonal polytypoid of CaZrTi2O7. Zirconolite-2M is the two-layered monoclinic polytypoid of CaZrTi2O7. Polymignite (metamict) is discarded as equivalent to zirconolite. Zirkelite is the cubic mineral with formula (Ti,Ca,Zr)O2−x.

Keywords: zirconolite • polymignite • zirkelite • mineral nomenclature

Mineralogical Magazine; December 1989 v. 53; no. 373; p. 565-569; DOI: 10.1180/minmag.1989.053.373.07
© 1989, The Mineralogical Society
Mineralogical Society (www.minersoc.org)