Ruby gold glass
Ruby glass was made by irradiating a soda-lime-silicate glass with ca. 0.2 weight % of
gold with gamma rays and further
heating instead of using a reducing agent such as
stannous oxide. Different colours were obtained by controlling the temperature and
heating times. A comparison of this process to develop ruby glass with the conventional
ones was made; using this novel process the colours can be better controlled and can be striked only after the artworks are finished.
The gamma irradiation facility used was a cobalt 60 source from the Portuguese Nuclear and Technological Institute.