1. CNR, ISMN, Chem. Dept., University of Rome “La Sapienza”, p.le Aldo Moro, 5, 00185-Rome, Italy
2. Technical University of Crete, Lab. of Petrology and economic Geology 73100 Chania, Crete, Greece
3. Mineralogy Petrography Dept,. Yerevan State University Alek Manukyan Str. 1, 375025 Yerevan, Armenia
4. Yerevan Physics Institute, Solid State Rad. Phys. Dept., Alikhanian Bros. Str. 2, 375036 Yerevan, Armenia
5. Tbilisi State University, Dept. of Materials, Chavchavadze ave. 1, 380028 Tbilisi, Georgia