Iolite, also known as Cordierite, is a mineral that exhibits a range of beautiful violet-blue to gray color variations. Also referred to as Dichroite, it has a pleochroic quality, meaning it reflects different colors depending on the angle of light. Other synonyms for Iolite include "water sapphire" due to its resemblance to the prized blue gemstone, and "Vikings' Compass" as it was used by the ancient Vikings for navigation due to its ability to transmit polarized light. Cordierite also finds its place in the lexicon as "Cat's Eye" Iolite due to the presence of chatoyancy or the cat-eye effect that lends it a unique appeal.