The blue gemstone often used in jewelry is sapphire. Sapphires are a variety of corundum mineral and are best known for their deep blue color, although they can come in a range of other colors, including yellow, pink, and green. Due to their hardness, ranking 9 on the Mohs scale, sapphires are highly durable and suitable for everyday wear in rings, necklaces, and earrings. The allure of sapphires has made them popular in fine jewelry and engagement rings. Historically, sapphires have symbolized wisdom, nobility, and royalty, adding to their desirability among jewelers and consumers alike.