Iolite

Iolite is sometimes called "Gem of the Vikings" or "Viking's Compass". The Vikings used thin pieces of it as the world's first polarizing filter. Looking through an iolite lens, they were able to determine the exact position of the sun, and navigate their way safely through the seas.The property that made iolite so valuable to the Vikings is its extreme pleochroism. Iolite has different colors in different directions in the crystal. A cube cut from iolite will look more or less violet blue, almost like sapphire, from one side, clear as water from the other, and a honey yellow from the top. The name is from the Greek "los", meaning violet. It has also been called "water-sapphire". The most desirable color is a rich violet-blue. While it is not as well known as its blue counterparts, sapphire and tanzanite, this pleasing blue gemstone is gaining widespread popularity for its beauty and its attractive affordability. Iolite is relatively hard, with a Mohs Hardness of 7 to 7.5, but should be protected from blows. With its attractive color and reasonable price, it may become a jewelry staple in the future.