This paper reports the first structure refinement of natural wangdaodeite, LiNbO3-type FeTiO3 from the Ries impact structure. Wangdaodeite occurs together with recrystallized ilmenite clasts in shock melt veins which have experienced peak shock pressures of between 17 and 22 GPa. Comparison of natural and synthetic wangdaodeite points toward a correlation between the distortion of ferrate- and titanate-polyhedra and the c/a ratio of the unit cell. The Raman spectrum of wangdaodeite is calculated based on the refined structure. Comparison to the reported spectrum of the type-material shows that the Raman peak at 738–740 cm−1 is indicative for this phase, whereas other features in type-wangdaodeite are tentatively assigned to disordered ilmenite.

Oliver Tschauner, Chi Ma, Matthew G. Newville, Antonio Lanzirotti, Structure Analysis of Natural Wangdaodeite LiNbO3-Type FeTiO3, Minerals 2020, 10(12), 1072 abstract

(a) SEM BSE image showing part of a wangdaodeite-bearing shock melt vein in Ries section ZLN114c; (b) enlarged BSE image of wangdaodeite and recrystallized ilmenite in contact with the shock melt vein; (c) a further enlarged BSE image showing individual crystallites of wangdaodeite and recrystallized ilmenite. The two minerals have the same composition within the resolution of the EPM analysis.