‘Biogenic Luminosity’ is a research project that questions ‘flat’ appearance and unsustainability of synthetic materials in comparison to those of biogenic and geologic origin. Biogenic materials are synthesized in benign conditions and although often extremely minuscule are highly expressive and effective, like structural colour commonly found in living organisms. Wall segment presented here investigates perceptual depth and radiance of such thin chromatic ‘veneers’ in the context of built environment. Ceramic tiles are veneered with living microbial colonies who self-assemble in a highly ordered three-dimensional microscopic bulk that exhibits iridescence and peculiar luminosity.