Proshchenkoite-(Y) from Russia - a new mineral species in the vicanite group: descriptive data and crystal structure
A REE-bearing fluorosilicate from the Tommot REE-Nb deposit in Yakutia, Russia, described without a name in 1966, is characterized here as a new species, proshchenkoite-(Y), of the vicanite group of borosilicates. Wavelength-dispersive electron probe analyses gave the following empirical formula: (Y3.70REE7.54Ca1.55Na1.16Mn0.77Th0.10Pb0.01)(Sigma 14.83)(Fe0.832+M0.15Ti0.02)(Sigma 1.00)Ca-1.00 (P0.
