Iolite beads (or Cordeirite) are a transparent and strongly pleochroic gemstone is dark blue, medium violetish blue and colorless. (Pleochroic minerals show different colors depending on which direction the viewer is observing the crystal.).Cordierite is named after the French geologist P. L. A. Cordier. The name Iolite is derived from the Greek ``los``, meaning violet. Iolite has been called `Water Sapphire` because of its resemblance to fine quality light Ceylon Blue Sapphire. Legendary 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. In choosing Iolite`s color, consider the tone of the blue and violetish blue so that you have a stone with only a slight hint of grey. Clean Iolite with warm water, a mild soap and a soft cloth then lay flat to dry. Iolite is mined in Sri Lanka (Ceylon), Myanmar (Burma), Australia, Namibia, Brazil, Tanzania, Madagascar, Connecticut, and Yellowknife, Canada.