Iolite

Iolite is an ancient gemstone that arguably doesn't get as much attention as it deserves today, perhaps because it's relatively abundant and not expensive to buy. However it still looks great and a deep blue iolite stone can look stunning in jewelry such as pendants, necklaces and bracelets.

What Is Iolite?

Iolite is the gemstone quality form of the mineral cordierite found in many places around the world. The name comes from the Greek word ios meaning violet and it's this violet blue colour that's normally associated with iolite.

Although iolite is usually thought of as blue it can vary considerably in colour. In particular the same stone will often have a diferent hue when viewed from different directions - usually bluish from one direction, yellowish from another.

Navigation

Iolite's multi-coloured property is known technicaly as pleochroism. This is a phenomenom associated with polarisation of light which once made it useful for navigators at sea. Even on a cloudy, overcast day a skilled navigator could determine the position by the colours of an iolite lens observed in different directions.

This navigational usage of iolite was definitely known to the early vikings such as Leif Eriksson and the gem is sometimes called the Vikings' Compass. I've never heard of it being used by medieval pirates however I wouldn't be surprised if a few of them kept a sliver of iolite around for emergencies.