Iolite

The name iolite comes from the Greek word "ion" or "ios", which means violet. It has a delicate and quite pretty violet blue color that is unique among gemstones. This color has been compared to a light blue sapphire and because of this, it is sometimes known as "water sapphire". Iolite has rather extraordinary optical property. The gemstone displays different colors depending upon which angle it is viewed from. This effect is known as pleochroism. A cube cut from iolite will look more or less violet blue from one side, clear as water from the other, and a honey yellow from the top. If cut properly the gem will show it's best color from the front (or top) of the stone but if viewed from another angle it may appear colorless. This gem was known as the "Viking's Compass." The legendary Viking mariners used thin pieces of iolite as the world's first polarizing filter to determine the direction of the sun on overcast days. Looking through an iolite lens, they could determine the exact position of the sun and navigate safely.