The Aga Khan emerald brooch is a remarkable piece of jewelry, featuring a 37.41-carat square-cut emerald that is surrounded by twenty navette-cut diamonds, collectively weighing approximately 12.04 carats. This exquisite brooch, crafted by Cartier Paris, is notable for its even green color and exceptional clarity, making it an extraordinary find among emeralds, which often have inclusions. The unique shape of the emerald, described as thin and flat, gives the illusion of a larger stone while maintaining a consistent hue throughout, further enhancing its desirability.