Iolite is named from the Greek word ‘ios’, meaning “violet”. It is a silicate of iron, alumina, and magnesia, and has a bright blue color. This blue silicate mineral occurs as crystals or grains in igneous rocks, only as a result of contamination of the magma by aluminous sediment.

Iolite’s extreme pleochromism made this stone very valuable to the Vikings. Iolite projects different colors when viewed from different angles. Iolite was known as the “Viking’s Compass” due to its ability to track the direction of the sun on very overcast days. Viking mariners also used this stone as the very first polarizing filter. They could look through an iolite lens and determine the exact position of the sun, and thus be able to navigate safely.

Synthetic magnesium Iolite has a low thermal expansion and is used as a semirefractory material because of its resistance to thermal shock.

Iolite is found in regions of Sri Lanka, Burma, India, Madagascar and Brazil. It’s most desirable color is a rich violet-blue. It is commonly cut into traditional shapes, and used artistically to create necklaces, pendants, rings, and bracelets.