The Logan Blue Sapphire, a 422.99-carat cushion-cut gem housed in the Smithsonian, is renowned for its exceptional clarity and rich blue color, showcasing the finest qualities of Ceylon sapphires. Its deep blue hue, attributed to natural geological conditions in Sri Lanka, enhances its immense value. With origins linked to Indian royalty and a storied history involving prominent figures, it represents a pinnacle of gemstone excellence. The sapphire’s rarity and untreated status significantly increase its worth, estimated at €15-25 million. It inspires collectors and symbolizes Ceylon’s remarkable gemstone heritage, captivating enthusiasts worldwide.