Sapphire, a hard and clear gem, is a variety of the mineral corundum. The best-known sapphires are blue. Their color results from small amounts of iron and titanium in the stone. Sapphires are also found in many other colors, including yellow, green, white, black, violet, and orange. Nonblue sapphires are called fancy sapphires. The red variety of corundum is known as a ruby.