There are presented the results obtained concerning the optimum synthesis conditions of the pink pigments, which result from the inclusion of chromium as chromophore in the crystalline structure of malayaite, CaO∙SnO2∙SiO2 (also known as tin sphene). Starting from mechanical mixtures of calcite, cassiterite and quartz with a mineralizing addition of 3% PbO and 2% Li2CO3 there have been obtained intense reddish-pink pigments, by annealing at 1250ºC for 3 hours. The pigment with molar ratio CaO:SnO2:SiO2=1:1,2:1 presents the same phase composition (malayaite and cassiterite) and the same VIS diffuse reflectance spectrum as a similar imported pigment, which is usually being used in the ceramic industry. Testing the obtained pigment in coloring some tableware faience glazes proved a better behavior by comparison to the reference pigment.

 

 

Back to Contents