Iolite or Cordierite that is named after the French geologist P.L.A. Cordier is a magnesium iron aluminium cyclosilicate. It is one of the most commonly used gemstone variety that exist in the Cordierite group.
Iolite is named from the Greek "ios" or violet, it has also another ancient Greek name which is: "dichroite".
Iolite typically occurs in contact or regional metamorphism of argillaceous rocks. It was also known as water sapphire in the ancient days.
The most desirable variety of Iolite is the rich violet blue one. It is usually a purplish blue when cut properly, with softness to the color that can be quite attractive. It is more common to find Iolite with a blue color in small sizes and the most common shape of it is oval.
Iolite is found in Brazil , India , Mozambique , Sri Lanka and Zimbabwe
The hardness of Iolite according to the Mohs scale is: 7-7.5.
