Spring Sale! Entire Site 25% Off! Code: SPRING25

Whale Tale Blog


All About Iolite or the “Water Sapphire”

All About Iolite or the “Water Sapphire”

All About Iolite or the “Water Sapphire”


Beth Pernerewski

Facebook Logo  Twitter Logo 


Iolite is the transparent, gem quality version of the mineral Cordierite. Cordierite is a silicate mineral that is found in metamorphic and igneous rocks and is typically blue to violet in color. Iolite’s appearance is similar to both sapphire and tanzanite. Iolite has also gone by the name “water sapphire” (what a great name!) because a piece could look like a sapphire from one direction but when turned, look as clear as water. Pleochroism is the name for a substance that looks one color from one direction and a different color from another direction.

Iolite has also been called “Viking’s Compass”. Iolite’s pleochroism allowed the Vikings to use thin slices as light polarizers to navigate their expeditions. By observing the sky through a slice of iolite, Viking navigators were able to locate the exact position of the sun on overcast days. The iolite canceled out haze, mist, and clouds to make things appear clearer.

The word iolite comes from the Greek word for violet, ios. Iolite is found in locations around the world, including my home state of Connecticut. The largest iolite crystal was found in Wyoming, weighing in at an impressive 24,000 carats. Today, iolite is the gemstone for the twenty-first wedding anniversary. It can be used in earrings, necklaces, and a variety of other pieces of jewelry.