Citation: Hawthorne, F.C.; Cooper, M.A.; Grice, J.D.; Ottolini, L. (2000). A new anhydrous amphibole from the Eifel region, Germany: description and crystal structure of obertiite, Na Na2 (Mg3 Fe(3+) Ti(4+)) Si8 O22 O2. American Mineralogist, 85, pp. 236-241.