Studies of the orthoamphiboles. IV. Mössbauer spectra of anthophyllites and gedrites

Abstract

Fitted M6ssbauer spectra are presented for a set of anthophyllites and gedrites. Despite their complexity it is possible to obtain fits for gedrite spectra and the M6ssbauer parameters are consistent with results for anthophyllites from this and previous studies. At least three doublets are required to fit the Fe 2+ absorption in gedrites; there is no single model at present to explain the behaviour of the spectra. Fe 3+ absorption is also resolved. K E Y W O R D S: orthoamphiboles, M6ssbauer spectra, anthophyllites, gedrites.

Long-Range Order in Amphiboles

“…Also apparent from Figure 16a is the fact that the degree of order of Fe 2+ at M(4) relative to M(1) [or M(2) or M (3)] is strongly sensitive to the temperature of equilibration. Similar results have been obtained for the orthorhombic Mg-FeMn amphiboles (e.g., Bancroft et al 1966;Law 1981;Seifert 1977Seifert , 1978.…”