Iolite 6x8mm Triangle Cut Faceted Rice Bead - 15-16 Inch Shape_Drop They are all varieties of

They are all varieties of the mineral corundum

aluminum oxide and other metal oxides

gray and mauve stone

and has been discovered with artifacts from cultures of the Neolithic Period

Many stones in the Russian crown jewels from the 17th century which were thought to be rubies are actually red Tourmaline

Iolite 6x8mm Triangle Cut Faceted Rice Bead - 15-16 Inch Shape_Drop They are all varieties ofIolite most commonly occurs in shades of blue to gray, violet or indigo. It displays a visual property called pleochroism, which means that it can appear to be different colors as it shifts in the light. According to Norse legend, Viking explorers used thin pieces of Iolite as the worlds first polarizing lens to help them determine the exact location of the sun for navigation.