A variety of intermediate-range structures have been found in crystals and borate units involving three-membered boron rings (3-rings). The final structures obtained via melt-quenching synthesis of borate glasses is the result of an equilibrium obtained through a process of repeated bond formation and cleavage in the molten state. Experimental studies of structural changes from glass melts to solidification have been limited due to the limitations of experimental setups. High-temperature Ramanscattering experiments with pure borate and binary sodium borates have been performed over the range from 1200 • C to room temperature. The boroxol rings in pure borate glass tend to be destroyed by thermal excitation in the molten state; 37 however, equilibrium reactions between boroxol rings and non-ring borate units in the molten state have been proposed for binary sodium borate melts. The conversion reaction from BO 4 to BO 3 and non-bridging oxygen has also been observed in glasses above 20 mol. % sodium content.