1. Sobolev Institute of Geology and Mineralogy, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia
2. Novosibirsk State University, Department of Solid State Chemistry, 630090 Novosibirsk, Russia
3. Bayerisches Geoinstitut, Universitat Bayreuth, D-95440 Bayreuth, Germany