Iolite: Vikings’ Compass
Iolite is magnificent gemstone that has very strong pleochroism. Usually changing colors from blue to blue violet and yellowish gray/colorless.
The best part is that because it can be found in abundance it is far cheaper than either of these and for this reason it has been steadily growing in popularity.
What is Iolite?
Iolite is the transparent gem quality variant of the mineral cordierite. The name iolite is derived from the Greek word for violet.
The gemstone can be found in the colors blue, violet, greenish, yellow and gray/colorless, depending on what angle the light comes from.
Usually it is cut in such a way that the blue or violet color is in view. Though this is not always possible when dealing with lower quality gemstones, these usually show different colors when viewed from above when set in jewelry.
Iolite is a fairly common gemstone that can be found all over the world. Countries where it is mined include Burma, India, Brazil, Sri Lanka, Canada and the USA.
History of Iolite
One of the most astonishing properties of iolite is that you can determine the position of the sun even when the sun is not in view. For example when it is clouded, foggy or when the sun has just set. This made it extremely valuable for navigating the seas.
Reportedly the Vikings used this gemstone for their journeys to other countries. It is likely that they mined iolite in Norway and Greenland though currently there is no commercial mining in these countries.
For this property and the fact that it is a blue gemstone it has been named ‘water sapphire’, but that name is hardly in use these days.
Taking Care of Your Iolite Gemstones
Iolite has a hardness of 7 to 7.5 on Mohs hardness scale. This means that it is suited for jewelry.
However because of the cleavage of the crystal you should be careful about bumping into things or dropping it. As it could chip or even shatter if you are unlucky.
Because of its fragility you might be better off if you stick to iolite earrings or necklaces instead of iolite rings. This will further remove this precious stone from harm’s way.
Iolite jewelry should not be placed in an ultrasonic jewelry cleaner. It can be cleaned in a jewelry steam cleaner though it is probably best to just stick to the following method: Use lukewarm water and some soap and a soft brush to thoroughly clean the gemstone. Make sure to dry it well before storing it away from other gemstones which can scratch it.
Iolite Buying Guide
The most important property of the iolite gemstone is its color. A rich violet blue color that resembles tanzanite is the most expensive, though a deep blue that looks like high quality blue sapphire is prized as well.
Cut is crucial for this gemstone, make sure that your gemstone displays different colors when you view it from different angles. If cut in the wrong way the pleochroism it is known for might be lost.
However most of these stones never make it to the market, because they often lose all color. Usually a round brilliant cut displays the different colors best and often sell for a premium.
If you want to buy iolite for its pleochroic properties you should buy a slightly larger stone. Iolites of three carats and up should properly display the color rotation.
Currently there are no known enhancements of iolite, there are rumors of some dyeing but this usually ruins the pleochroism so if your stone does display this it likely has not been enhanced.
Iolite is fairly cheap and unknown so it is not widely imitated. The usual quartz and glass imitations are of course on the market, but these show no color rotation at all and should be easy to spot. Iolite itself is used to imitate high quality blue sapphires or tanzanite, but this is of little concern to you if you want an iolite in the first place.