Sapphires are one of the hardest gemstones, second only to diamonds on the Mohs scale of mineral hardness. This makes them a perfect choice for jewelry that’s worn daily, like engagement rings. They are made of a mineral called corundum, and their colors can range from blue (the most well-known) to pink, yellow, and even clear. The color of the sapphire is determined by the trace elements present within the corundum. For instance, iron and titanium can give a sapphire its classic blue color.
