African Oval Iolite with Grey-Blue Colour Change

About Iolite

Iolite is the transparent to translucent gem variety of cordierite, an orthorhombic magnesium-iron aluminium silicate. Its colours range from soft blue and violet-blue to greyish, yellow-brown or nearly colourless tones. Its most remarkable feature is strong pleochroism: the colour appears different when the stone is viewed in different directions. A well-oriented cut can therefore show an attractive blue face-up colour,…