Its glare is vitreous, a bit fatty on the break. On this one, one observes sometimes a significant shimmer. Inclusions, similar to dust, are represented by carbonaceous substances, zircon crystals and mica. The fields of cordierite are in the magmatic and metamorphic rocks in Tanzania, in Sri Lanka, in Madagascar, in Brazil, in Burma and Norway. Cordierite resembles especially the tanzanite, sapphire, the blue spinel and indigolite tourmaline.