The name Iolite comes from the Greek word ios which means "violet". Iolite is usually a purpleish blue color when cut properly. Legend has it that the Vikings used rough iolite stones to find the direction of the sun on overcast days to allow them to navigate their boats. Hence the name "Vikings' Compass" for this gemstone. When Leif Eriksson and the other legendary Viking explorers ventured far out into the Atlantic Ocean, away from any coastline that could help them determine position, they had a secret navigational tool: iolite. These 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. It is the property of pleochroism that made this stone so valuable to the Vikings. It is this same property that is a nightmare for the gem cutter. If it is not cut from the right direction, it will not have the same appeal.