Cordierite, also known as iolite in its gem form, is a beautiful mineral that changes colors depending on your angle of viewing. When light reflects off this magnesium rich compound, it creates an enchantingly beautiful display that varies from gray to yellow and violet to blue. On rare occasions, this fireworks-like display includes deep reds and browns creating a near riot of colors for the eyes. Read below to learn how this beautiful rock is created, how it was discovered and how it is made into one of the most beautiful and fascinating gems known to man.

The Discovery of Cordierite

blue Cordierite crystal

Cordierite is named after the French mineralogist Pierre Louis Antoine Cordier, who described it in 1813. Of course, it’s been around and used much longer than that. The stone was valued by the Vikings as a filter to polarize sunlight for navigation. This would help them find the direction of the sun even on a cloudy day.

Despite the fact that it’s been known of for centuries, it’s fairly new on the gemstone market. This is largely because there were no large, gem-quality discoveries of this crystal until very recently. Roughly 20 years ago, a very large gem-quality deposit of cordierite was discovered in Grizzly Creek, Wyoming. The deposit contained the largest known iolite crystal in the world, weighing a whopping 24,000 carats.

Properties of Cordierite

Cordierite used to be marketed under the very misleading name “water sapphire.” This is because a very well-cut gem will reflect the blue color qualities of a sapphire from the top angles, only changing color to clear or brown from the sides.

This color changing quality classifies cordierite as a pleochroic gemstone. It fact, it’s the most pleochroic gemstone known to date. This quality is caused by the fact that light is doubly refracted by the crystals. In the case of cordierite,  it’s triply refracted, as these gems are trichroic. This means that you can see three colors in the gem, all at the same time, depending on which angle you are viewing it from. In some angles of a well-cut gemstone, it even appears as crystal clear as water.

trichroic cordierite

Magnesium aluminum silicate Mg2Al3[AlSi5O18] make up the chemical structure of this stone, but some can be found with visible occlusions of other minerals. Some rare cordierite crystals even have a cat’s eye asterism. While pure gems are sought after for jewelry and decoration, stones with occlusions are valued by mystics for their meditative properties.

Metaphysical Details About Cordierite

Cordierite is thought to help open the third eye by clearing the path from the crown to the throat Chakra. This can help to guide the way for deep revelations about one’s inner thoughts. Focusing on occlusions within an imperfect crystal makes a wonderful device to deepen and clarify meditational concentration and self-exploration. This can significantly increase inner intuition, thus enhancing the meditator’s natural gifts. Clairvoyants find these beautiful gems useful to increase accuracy of their prophecies and visions.

Jewelry Containing Cordierite

cordierite necklace

There aren’t many famous examples of cordierite jewelry, as it’s such a rare gem. In fact, if you were to walk into any gem store in North America, you’d be hard pressed to find a cordierite/iolite ring for sale.

The most famous examples of cordierite are those gemstones used by the Vikings to find their way at sea. Cordierite was not the only crystal used for this purpose, but many examples of cordierite sun stones have been found around Viking haunts. In fact, it’s become a rather cool inspiration for cordierite compass pendants.

It takes a very skilled gem cutter to make a cordierite crystal suitable for a jewelry setting. This is because if the cut is even slightly flawed, it can completely destroy the color of the crystal. If it is cut perfectly, however, it can be mistaken by even well-trained jewelers for a high quality sapphire.

Of course, the stone has to have the perfect color to serve this purpose, and not many iolite stones do. Some are overly dark while others have more of a murky flaw that can’t be corrected with heating. Iolite gems that lack clarity are often cut in a cabochon form, meaning that the gem is polished to a round, rather than faceted. In this form, they still add a beautiful dark blue color to settings at a very affordable price.

Where Do We Find Cordierite Today?

Cordierite, oddly, is not as sought after as many other more expensive gems, even though it is quite rare. In fact, it’s often used as a substitute for sapphire because it’s less expensive. We can find it on nearly every continent now, with deposits in India, Sri Lanka, Northern Australia, Burma, Brazil, Namibia, Madagascar, Tanzania, Canada and the United States. Most of the mining takes place in Sri Lanka. Prospectors often look for the crystals, as they are coming into more demand. The method is somewhat different than panning for gold.

The best chance a prospector has to find the crystal is to look for it inside aluminum-rich stones. Recently, in 2014, a prospector filed a claim for an iolite find in Wyoming. It wasn’t easy for him to find the deposit as he was attempting to find the outcrop with a backhoe, digging through the softer soil. Once he dug the trench across the gneiss (a form of high grade metamorphic stone), he turned up a huge deposit. Unfortunately, most of the iolite was not gem quality because the value of it had been diminished by crushing and grinding of a shear zone. This is one of the reasons that high quality iolite is a rarity in the jewelry world.

Final Thoughts

With its amazing, beautiful and very useful qualities, it’s surprising that cordierite gems are so inexpensive. Despite their rarity, a little online shopping will turn up several interesting options for iolite jewelry and gem stones. Will the price of this dazzling gem rise as more connoisseurs become aware of its amazing metaphysical and refractory properties?