, 2020). This sort of will increase in both peak absorption cross section and width in the 450 nm absorption band more than linearly increase the toughness of the chromophore with focus. Other chromophores in natural corundum will not show these changes and thus show a constant toughness with focus. https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share