The 56. 07-carat Tavernier pear-shaped gent diamond not only has an important historical provenance, but also shows a substantial color change between incandescent light and daylight. This famous diamond exhibits a very strong blue fluorescence when exposed to long-wavelength ultraviolet (UV) radiation. It appears light brown (an orange hue) under incandescent light, and light pink (a purple hue) under daylight. This change in color or ＇＇alexandrite effect,＇＇ is caused by its very strong blue fluorescence resulting from the long-wavelength ultraviolet component present in daylight.