Way to glow! The 127.01 carat Ascher cut Portuguese Diamond is a spectacular example of an “overblue” diamond. That means when it is exposed to ultraviolet (UV) light, its fluorescence is so strong that it looks hazy or oily under sunlight. While “overblue” diamonds aren’t typically sought after, the intense fluorescence of this diamond, combined with its large size and history, make it remarkable. Harry Winston purchased the Portuguese Diamond in 1951 and traded it to the Smithsonian Institution in 1963 in exchange for 3,800 carats of smaller diamonds.
