Germanic Sulphide, GeS₂

Germanic Sulphide, GeS₂, probably occurs naturally in argyrodite. It is obtained as a voluminous white precipitate by passing hydrogen sulphide through a solution of germanic oxide, or by adding mineral acid to a solution of germanous sulphide, GeS, in yellow ammonium sulphide. Weak organic acids, such as acetic acid, do not precipitate this solution owing to the stability of the complex thio-germanic ion which is present; and indeed a large excess of mineral acid must be used to complete the precipitation.

Germanium disulphide is a white powder difficult to wet with water, but soluble in 221.9 parts of water, forming a solution which will precipitate various less soluble metallic sulphides. The aqueous solution quickly decomposes, with evolution of hydrogen sulphide. This sulphide readily dissolves in alkali hydroxide solution with formation of thio-germanate, a derivative of thio-germanic acid which is probably H₂GeS₃.