Iridescent Techniques in Ceramics: Physico-Chemical Analysis and Colorimetric Characterization of the Headquarters of the Botín Foundation in Santander

In recent years, the use of porcelain stoneware in building envelopes has opened new lines of research and innovation favoring energy efficiency and the reduction of environmental impacts. However, there has been little research on its relationship with light vibration and reflectivity, visual perception, and integration in the urban environment and landscape. In this study, an analysis was conducted on the production and application of crafted pieces of porcelain stoneware, shaped in spherical caps, at the headquarters of the Botín Foundation in Santander (Spain). Various enamels with an iridescent-nacreous finish and metallic reflection were applied to the stoneware to generate a vibrant skin that would constantly change with natural light and the environment. A vitrification and metal deposition process were designed through successive applications of enamels and firings. The physico-chemical properties of the enameling and the microcracking factors that produced the iridescent effect were characterized. A colorimetric characterization was performed evaluating the goniochromatic or iridescent colors, measuring the spectral radiance factor of the light, and comparing these results with other ceramic pieces.