Sid-Ali Kechid, Gian Carlo Parodi, Sylvain Pont, Roberta Oberti; Davidsmithite, (Ca,□)2Na6Al8Si8O32: a new, Ca-bearing nepheline-group mineral from the Western Gneiss Region, Norway. European Journal of Mineralogy 2017;; 29 (6): 1005–1013. doi: https://doi.org/10.1127/ejm/2017/0029-2667