Thermally metamorphosed argillaceous sedimentary rocks; high-grade regionally metamorphosed schists, gneisses and granulites; also in mafic igneous rocks and granites.
Περιγραφή:
Thermally metamorphosed argillaceous sedimentary rocks; high-grade regionally metamorphosed schists, gneisses and granulites; also in mafic igneous rocks and granites.