Mg2Al4Si5O18 - Complex Magnesium Aluminium Silicate
The name iolite comes from the Greek ios, which means violet. Iolite is usually a purplish blue when cut properly, with a softness to the color that can be quite attractive. This purplish-blue gemstone (Cordierite) is sometimes known as the "water sapphire" owing to it's resemblance in color to the more valuable blue sapphire. Properly cut, iolite shines different colors when viewed from different angles, a quality known as "pleochro. More on...
Colors: Ranges from blue to violet
Care and Treatment
Aventurine has a hardness rating of 7.
Specific Gravity: 7.0 to 7.5
Iolite is most commonly found in Sri Lanka, India and Madagascar, and was long ago mined in Norway and Finland. Viking mariners are thought to have used thin pieces of iolite as the first polarizing lens, a navigational tool used to determine the exact position of the sun.
Star Stone Months
The Viking mariners used thin pieces of iolite as the world's first polarizing filter. Looking through an iolite lens, they could determine the exact position of the sun, and navigate safely to the new world and back.