Recrystallization of metamict allanite

摘要

Allanite is a common accessory mineral in igneous rocks. Allanite becomes metamict over geological time-scales as a result of the a-decay of radioactive elements in the crystal structure. This study focuses on the recrystallization of metamict allanite from Savyushka, Russia. The structural recovery produced by annealing was investigated by X-ray powder diffraction, single-crystal synchrotron X-ray diffraction and infrared spectroscopy. A kinetic analysis is presented that shows that the recrystallization process proceeds by at least two different mechanisms.