Serpentinites of the melange zone in the north of the Ray-Iz massif, hosting gem garnet (andradite-demantoid)

Abstract

The chemical composition was studied; spectroscopic (FTIR, EPR) and X-ray diffraction analyses of serpentines from the host rocks of gem garnet andradite-demantoid occurrences of their melange zone in the northern part of the Ray-Iz massif were carried out. The quantitative species composition of the serpentinites was determined by the method of synchronous thermal analysis. We found that serpentines were represented by three varieties of lizardite-1T and chrysotile-2Mcl in sample PTM-1 and chrysotile-Orcl in sample PTM-2. The complex of conducted studies allowed specifying the mineral composition of the studied serpentinite samples and greenschist (chrysotile) facies of progressive contact metamorphism.