Blue Diamond is a rare variety of diamond composed of pure carbon (C) and belongs to the native element mineral group. It crystallizes in the cubic (isometric) crystal system and is one of the most valuable gemstones in the world. The distinctive blue color of this diamond is caused by trace amounts of boron within its crystal structure, which also gives it unique electrical conductivity—an unusual property for a gemstone. Blue Diamonds range in color from faint blue to deep, vivid blue. The most valuable stones are those with intense, saturated color, often referred to as “fancy vivid blue.” These diamonds are usually transparent and exhibit exceptional brilliance due to their high refractive index and superior light performance.