Spray of hydroastrophyllite in alkaline granite pegmatite matrix. Chemical composition of mineral from this specimen is (H3O1.19Ca.75K.51Ba.37Sr.18)3.00(Fe"5.75Mn.27)6.00(Ti1.60Fe"'.39)1.99(Si6.56Fe"'.81Al.63)8.00(O23.43(OH)7.57)31.00. As we can see, usual for astrophyllite Na is absent, K is depleted in this formula and are replaced by exotic for it Ca,Ba and Sr. The locality is situated on the boundary between alkaline granites of Western Keivy massif and alkaline basites of Sakharijok massif. Associating minerals are pink microcline grains and brown prismatic zircon crystals. In such zircons from this locality microinclusions of hydroxylbastnasite-(La) were discovered. FOV is ~12x9 mm. Collected by Arkadii Shpachenko in the end of 80th. Pavel M. Kartashov collection and photo.
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