It also forms as a passivation layer on pure germanium in contact with atmospheric oxygen.

[3] At higher pressures, up to approximately 15 GPa, the germanium coordination number increases to 6, and the dense network structure is composed of GeO6 octahedra.

[6] GeO2 is only slightly soluble in acid but dissolves more readily in alkali to give germanates.

[7] In contact with hydrochloric acid, it releases the volatile and corrosive germanium tetrachloride.

The glass can be manufactured into IR windows and lenses, used for night-vision technology in the military, luxury vehicles,[8] and thermographic cameras.

Silica-germania glasses have lower viscosity and higher refractive index than pure silica.

It gives the glass a very reactive/changeable color, “a wonderful rainbow effect” when combined with silver oxide, that can shift light amber to a somewhat reddish and even deep purple appearance.

For this application, the concentration of germanium dioxide typically used in the culture medium is between 1 and 10 mg/L, depending on the stage of the contamination and the species.