First find of banalsite-stronalsite in Ural

Minerals of the banalsite-stronalsite group Ba1-xSrxNa2Al4Si4O16 - structural analog of the feldspar - were for the first time discovered in alkaline rocks of Ilmenogorsky miaskite massif (IMM) by microprobe study of sandyite. This discovery is important for evalution of mobility of Ва, Sr, Ca in alkali metasomatic procceses. Minerals are located inside individuals of nepheline from sandyites and they are characterized by intermediate compositions Ba0.33-0.54Sr0.33-0.49 with lisetite minal Сa0.05-0.06. Their formation in sandyites of Ilmenogorsky complex is related to the late metasomatic modification (albitization, zeolitization and others) of IMM alkaline rocks.