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  1. No Access

    Article

    A combined temperature dependent57Fe Mössbauer and single crystal X-ray diffraction study of synthetic almandine: evidence for the Gol'danskii-Karyagin effect

    Synthetic almandine garnet, Fe3Al2Si3O12, has been studied by temperature — dependent single crystal X-ray diffraction and57Fe Mössbauer spectroscopy. The Fe2+ doublet in almandine is characterized by a small asy...

    C. A. Geiger, Th. Armbruster, G. A. Lager, K. Jiang… in Physics and Chemistry of Minerals (1992)

  2. No Access

    Article

    Prediction of refractive indices in minerals from crystallographic data: Applications and limitations of the point-dipole model

    A point-dipole calculation which incorporates an expression for the Lorentz-factor tensor has been used to model the effect of chemical substitution on refractive index and optic axial angle (2V). Isotropic elect...

    G. A. Lager, Th. Armbruster, D. Pohl in Physics and Chemistry of Minerals (1987)

  3. No Access

    Article

    Cordierites from the Lepontine Alps: Na + Be → Al substitution, gas content, cell parameters, and optics

    Na, Be cordierites (Alpe Sponda) and normal Na-, Be-poor cordierites (Miregn) from the same tectonic unit are compared. The Alpe Sponda samples (Na2O: 1.1–1.5 wt.%, BeO: 0.6–0.8 wt.%), which occur in paragonite m...

    Th. Armbruster, A. Irouschek in Contributions to Mineralogy and Petrology (1983)

  4. No Access

    Article

    Very high CO2 cordierite from Norwegian Lapland: Mineralogy, petrology, and carbon isotopes

    The most CO2-rich cordierite thus far encountered in nature with about 2.2 wt.% CO2 and 0.3 wt.% H2O occurs as large poikiloblasts in a strange non-foliated “reaction rock” that dissects well-foliated granulites ...

    Th. Armbruster, W. Schreyer, J. Hoefs in Contributions to Mineralogy and Petrology (1982)