When it comes to precious stones, rarity and demand determine their price. While diamonds are often assumed to be the costliest, they are eclipsed by certain colored gems. The rarest stone, priced at a staggering $3 million per carat, is the Pink Star Diamond. However, if we consider commercially available stones, it’s the Blue Diamond that reigns supreme, with prices up to $3.93 million per carat. Rarity and aesthetics dictate the exorbitant prices, making these stones the ultimate symbol of luxury and exclusivity.