White sapphire is a colorless gemstone that belongs to the corundum mineral family, which also includes rubies and sapphires in various colors. It is composed of aluminum oxide and is known for its hardness, ranking 9 on the Mohs scale, making it an excellent choice for jewelry. Unlike diamond, which is often sought for its brilliance, white sapphire has a different type of luster and can appear more subdued. It is often used as a more affordable alternative to diamonds in engagement rings and other fine jewelry, offering durability and beauty without the high price tag.