Boiling Point: 1245 ℃

TeO2 is highly insoluble in water and soluble in concentrated sulfuric acid. (According to reference 4 Tellurium dioxide is soluble in water, p59. Tellurium trioxide is insoluble in water, p56). It is also incompatible with strong acids and strong oxidizing agents. It is an amphoteric substance and therefore can act both as an acid or as a base depending on the solution it is in. It reacts with acids to make tellurium salts and bases to make tellurites. It can be oxidized to telluric acid or tellurates.

It is used as an acousto-optic material.

Tellurium dioxide is also a conditional glass former, which means it will form a glass with small molar% additions of a second compound such as an oxide or halide. TeO2 glasses have highrefractive indices and transmit into the mid-infrared part of the electromagnetic spectrum, therefore they are of technological interest for optical waveguides. Tellurite glasses have also been shown to exhibit Raman gain up to 30 times that of silica, useful in optical fibre amplification.