Anisotropy of magnetic susceptibility in alkali feldspar and plagioclase

Biedermann, Andrea R.; Pettke, Thomas; Angel, R. J.; Hirt, A. M. (2016). Anisotropy of magnetic susceptibility in alkali feldspar and plagioclase. Geophysical journal international, 205(1), pp. 479-489. Blackwell Science 10.1093/gji/ggw042

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Feldspars are the most abundant rock-forming minerals in the Earth’s crust, but their magnetic properties have not been rigorously studied. This work focuses on the intrinsic magnetic anisotropy of 31 feldspar samples with various chemical compositions. Because feldspar is often twinned or shows exsolution textures, measurements were performed on twinned and exsolved samples as well as single crystals. The anisotropy is controlled by the diamagnetic susceptibility and displays a consistent orientation of principal susceptibility axes; the most negative or minimum susceptibility is parallel to [010], and the maximum (least negative) is close to the crystallographic [001] axis. However, the magnetic anisotropy is weak when compared to other rock-forming minerals, 1.53 × 10−9 m3 kg−1 at maximum. Therefore, lower abundance minerals, such as augite, hornblende or biotite, often dominate the bulk paramagnetic anisotropy of a rock. Ferromagnetic anisotropy is not significant in most samples. In the few samples that do show ferromagnetic anisotropy, the principal susceptibility directions of the ferromagnetic subfabric do not display a systematic orientation with respect to the feldspar lattice. These results suggest that palaeointensity estimates of the geomagnetic field made on single crystals of feldspar will not be affected by a systematic orientation of the ferromagnetic inclusions within the feldspar lattice.

Item Type:

Journal Article (Original Article)


08 Faculty of Science > Institute of Geological Sciences
08 Faculty of Science > Institute of Geological Sciences > Rock-Water Interaction

UniBE Contributor:

Biedermann, Andrea Regina, Pettke, Thomas


500 Science > 550 Earth sciences & geology




Blackwell Science




Thomas Pettke

Date Deposited:

21 Jun 2016 10:47

Last Modified:

28 Dec 2023 01:26

Publisher DOI:





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