It Is Highly Durable

  Yellow sapphire is a member of the corundum family, which includes rhodolite garnet, ruby, pink sapphire, and padparadscha. Although it is often treated as a gemstone, it is a member of the larger corundum family. It’s a relative of a ruby!   Corundum is one of the hardest minerals on Earth. It has only two gemstones: ruby and sapphire. Diamonds are harder than any other natural material on Earth, but they are not the hardest material used in jewelry—corundum (ruby and sapphire) have that honor.