the Mid-Atlantic ridge between Iceland and Jan Mayen. The extremely low Fa content of this olivine is...Min., 11, 15868). 6 Nontronite, Andreasberg, Germany (Brigatti, M.F., 1983, Clay Min., 18, 17786)....Sanidine, leucite-nepheline dolerite, Vogelsberg, Germany (Tilley, C.E., 1958, Amer. Min., 43, 75861). Anorthoclase...haüyne-feldspar ejectamenta, Thelenberg (Laacher See volcanics), Germany (Taylor, D., 1967, Contrib. Mineral...in the volcanic rocks of the Eifel district of Germany (Table 43, analysis 4). Lazurite occurs in lapis |