The top four gemstones are diamonds, sapphires, emeralds, and rubies. Diamonds are the most popular, known for their brilliance and hardness, making them the traditional choice for engagement rings. Sapphires, prized for their deep blue hue, are also popular, especially in high-end jewelry. Emeralds, with their rich green color, are associated with luxury and are highly valued. Rubies, known for their vibrant red color, are also among the most sought-after gemstones for their beauty and rarity.