- Gem of the Vikings. When legendary Viking explorers ventured
far out into the Atlantic Ocean, far away from any coastline,
they had a secret gem weapon: iolite. 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
The property that made iolite so valuable to the Vikings is
extreme pleochroism. Iolite has different colors in different
directions in the crystal. A cube cut from iolite will look
a violetish blue almost like sapphire from one side, clear as
water from the other, and a honey yellow from the top. This
property led some people to call iolite "water sapphire"
in the past, a name that is now obsolete.
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.
Iolite is readily available and surprisingly affordable. The
better and richer the blue, the better. It is mined in India,
Sri Lanka, Mozambique, Zimbabwe, and Brazil.
Iolite is relatively hard but should be protected from blows.
With its attractive color and reasonable price, it may become a jewelry
staple in the future.