A Geoscience Digital Image Library

DescriptionCordierite is a silicate with the mineral formula of Mg2Al4Si5O18. Cordierite is not a well known mineral but its gemstone variety iolite is popular among gemstone collectors. Its unusual blue-violet color is attractive and is compared to a light blue sapphire with a purplish tint. Cordierite is strongly pleochroic and is sometimes referred to by the synonym dichroite a greek word meaning two colored rock. This sample is approximately 7 cm.
LocationCanada ▹ Ontario. Near Chapleau.
PhotographerShannon Heinle. 2001-11-29.
CollectionUniversity of North Dakota Mineralogy Collection #5008.
Key wordscordierite, iolite, silicate
Tech details490 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens.
GeoDIL number1862