Iolite is the gem variety of the mineral Cordierite. It describes the transparent to translucent form of Cordierite, and it has recently become a popular gemstone. Iolite can be light to deep blue, and usually has a purplish tinge to it. Deeper colored stones are more valuable. Iolite is very affordable and durable, and can be used as a substitute for more expensive blue gemstones such as Sapphire. It is named from the Greek “violet”, alluding to the purplish tinge often exhibited by this gemstone.