Optical properties of gold (and other precious metals) in acetate glasses

Colors of gold ruby glasses are variable, depending in part on the size of the gold particulates dispersed in the colloidal state. In order to understand more fully the optical properties due to Au and other precious metals (Ag, Pd, Rh, Ru, Re) in silicate glasses, this study reports on the inclusion of such metals into analogous, low-melting acetate liquids and glasses. For example, the color imparted by gold in Na-K-Ca-acetate glasses versus Li-Pb-acetate glasses changes from pink to purple, as the nature of the colloidal dispersion is affected by the structure of the acetate system. Other precious metals can be incorporated into the acetates as colloidal dispersions or as ions, with the resulting colors controlled by the nature of the metal and the structure of the acetate system.