, 2020). These increases in the two peak absorption cross area and width on the 450 nm absorption band in excess of linearly enhance the toughness with the chromophore with concentration. Other chromophores in natural corundum do not clearly show these changes and so show a constant toughness with focus. https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share