engleski

Crystal-chemical properties of complex metamict minerals - allanite

Metamict minerals are minerals with damaged or destroyed crystal structure. They have been known since the beginning of the 19th century as a third class of amorphous substances. There are two causes for metamictization of minerals: radioactive decay of Th and U comprised in their crystal structure complexity of their crystal-chemical properties.Allanite has a general formula: CaREEAlAlFe2+[SiO4|Si2O7]O(OH) where REE = Ce, La, Nd, Y, and Th and U. Allanite readily appears metamict due to its rather complex crystal structure and chemical composition, along with the radioactive decay of most notably Th, but also U. Main purpose of investigating metamict minerals lies in the fact that they are natural analogues of radioactive waste disposal materials. Also, minerals containing radioactive elements Th and U are used for geochronology

HRTEM; allanite; recrystallization mechanism

nije evidentirano