The book is mainly an outcome of the original research work carried on borate glasses doped with single and two TM ions. In this book, the anomaly in glass science "Mixed Transition Effect" was discussed by the author in various physical parameters, polaron related parameters by fitting quantum-theoretical models such as Mott's SPH, Mott and Greaves VRH and Greaves VRH models for borate glasses doped with vanadium and cobalt. The results were compared with previous published work in international reputed journals. The book is more helpful for the researchers and students who are working in oxide glass composites.