Sodium-strontium mica - Na0.50Sr0.25Al2 (Na0.25□0.75)Al1.25 Si2.75O10(OH)2 from Rubinovy Log

Abstract

An extraordinary mica with the high content of Sr is found in chromite deposit. Chemical composition of new Sr variety of mica is determined by scanning electron microscopy. The high concentration of Sr (3.06-6.02 mass% SrO) allows to look Sr as the species forming element in mineral. An averaged empirical formula is deduced for new Sr mineral. The Na,Sr-mica studied and paragonite differ in structure, properties and chemical composition. It is not variety of paragonite and other natural known micas.