Blue Sapphire and Tanzanite are two popular gemstones used in stud earrings. While they may look similar, there are some key differences between the two that are worth exploring. Blue Sapphire is a precious gemstone that has been prized for centuries for its deep blue hue and durability, while Tanzanite is a relatively new gemstone that is known for its unique blue-violet hue. In addition to differences in appearance, there are also differences in hardness and price.