Iolite Also called Cordierite and Dichroite. The name comes form the greek word violet. Inclusions of Hematite and goethite can cause a reddish sheen. It has a mohls hardness of 7-7.5 and a refractive index of 1.542-1.578 Depsoits of this gem are rare found in Myanmar, Brazil, India Sri lanka and more recently in Madagascar.