Coupled substitution of H and minor elements in rutile and the implications of high OH contents in Nb- and Cr-rich rutile from the upper mantle
Article
Vlassopoulos, D, Rossman, GR, Haggerty, SE. (1993). Coupled substitution of H and minor elements in rutile and the implications of high OH contents in Nb- and Cr-rich rutile from the upper mantle
. AMERICAN MINERALOGIST, 78(11-12), 1181-1191.
Vlassopoulos, D, Rossman, GR, Haggerty, SE. (1993). Coupled substitution of H and minor elements in rutile and the implications of high OH contents in Nb- and Cr-rich rutile from the upper mantle
. AMERICAN MINERALOGIST, 78(11-12), 1181-1191.
Infrared absorption spectra of rutile crystals from a variety of geological environments exhibit strong absorption in the 3300-cm-1 region due to interstitial protons bonded to structure O. In general the proton is located at sites slightly displaced from 1/2 1/2 0 of the unit cell, although some samples show evidence of additional protons at tetrahedral interstitial sites. H contents of rutile range up to 0.8 wt% H2O, the highest concentrations occurring in mantle-derived Nb- and Cr-rich rutile of metasomatic origin. The role of H in rutile was examined, particularly with respect to its relations to other impurities. The possibility of using the H content of rutile as a geohydrometer is illustrated for the case of coexisting hematite and rutile. -from Authors
