Iolite is a bluish purple gemstone, which is growing in popularity. It's a fantastic example of a pleochroic gemstone, which means it shows different colours at different angles, with blue and yellow both being visible.

It's believed that Vikings used iolite as a polarising filter to help them find the sun on cloudy days, thus acting as a navigational aid.

This beautiful gemstone can sometimes be confused with tanzanite and blue sapphires.