Sapphire is a mineral that has a blue color and can scratch garnet. Sapphire is a variety of the mineral corundum, and it ranks higher on the Mohs scale of mineral hardness compared to garnet. The Mohs scale is a system used to measure the relative hardness of minerals based on their ability to scratch one another. Sapphire has a Mohs hardness of 9, while garnet typically has a hardness of 6.5 to 7.5, making sapphire capable of scratching garnet. To get more info you can visit the site CabochonsForSale.