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Iolite Gemstone – Everything You Need to Know Before You Buy

Iolite frequently asked questions

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Sometimes mistaken for more expensive sapphire or tanzanite, iolite is adored for its violet-blue color. It’s gaining popularity in jewelry design due to its beauty and affordability. If you’re thinking of purchasing iolite, here are the things you should know before you buy.

What is iolite?

Loose iolite gemstone

Loose iolite gemstone by NS Gems Shop. See it here.

Iolite is a variety of mineral cordierite, a transparent violet-blue gem known for thousands of years. The name iolite is derived from the Greek words ios and lithos, meaning violet and stone respectively. The mineral cordierite is named after Pierre Cordier, a French geologist who first studied it.

Iolite has been incorrectly referred to as water sapphire, as it resembles the blue gemstone in color, yet it tends to have a washed-out appearance or color zoning, featuring blue to violet hues on one side and pale yellow to colorless on the other. In fact, it’s a strongly pleochroic gem, in which you’ll see distinct colors such as blue, bluish-gray, or grayish yellow to colorless in different directions.

Notice the difference in colors in the three gemstones below, which are very similar at first glance, but have distinct differences.

Iolite vs tanzanite vs sapphire

Cordierite is the name used by geologists, but if the mineral is of gem quality, it’s called iolite in the jewelry trade.

Technically, this gemstone is a silicate of aluminum, iron and magnesium, and is found in alluvial gravels as water-worn pebbles. It’s often sourced from Sri Lanka, Africa, Brazil, Norway, India and Madagascar. Iolite is commonly used in jewelry because it of its appealing blue color and affordability.

What are iolite quality factors?

When purchasing iolite, you can use the 4Cs—color, clarity, cut, carat weight—to evaluate the gemstone.


Iolite’s most valuable color is a saturated violet-blue, making it comparable to tanzanite or sapphire. For a highly saturated iolite, opt for a medium dark tone. As much as you can, go for the most vivid, deepest blue you can find, though only a few of these gems display such high saturation.

Average iolite stones have a washed out or inky blue or grayish color. Even if iolite is blue, its strong pleochroism will display different colors when viewed from different angles. Some sections can look transparent, golden, grayish or brownish. Color zoning is also common, so some areas might display a dark color, while others might appear light. Look for stones with even saturation, tone and hue.


Usually, iolite is transparent with a few inclusions, but eye-clean iolite is the most valuable. Sometimes, iolite’s long, parallel, tubular inclusions can exhibit asterism, the cat’s eye phenomenon, when cut expertly.

On the other hand, metallic, plate-like inclusions can display the sparkly effect called as aventurescence, where the gemstone appears to have a metallic glitter within the crystal, caused by mineral platelets.

When inclusions in iolite are reddish or brownish in color, the gem is commonly called bloodshot iolite. Most iolites with hematite inclusions come from Sri Lanka. The gemstone’s optical effects are impressive, but these aventurescent and cat’s-eye gems are rare, and coveted by collectors.


Because of its strong pleochroism, it’s a challenge for gem cutters to bring out iolite’s best color. What’s more, iolite has perfect cleavage in one direction, which means it can easily break with extreme pressure, sharp temperature, or a hard blow. Apart from special care during cutting, polishing and mounting, it’s also advisable to set the stone in protective settings, or incorporate it to jewelry pieces that aren’t exposed to too much wear, like earrings and pendants.

A skilled cutter can bring out all the beauty the gemstone has to offer. You can find iolite in all shapes. Iolite can even be carved. They’re usually faceted but some stones are also polished into cabochons. Most of the time, iolite is step cut to enhance its color, as well as shallow cut to lighten its tone. However, lower quality stones are commonly fashioned into beads.

Carat Weight

Iolite as a mineral might not be rare, but fine faceted varieties over 8 carats are. This is because eye clean stones of such large sizes don’t come easily. In jewelry, iolite is inexpensive between 1 to 5 carats. However, eye clean gems of around 15 to 20 carats are worthy of museum display.

How much does iolite cost?

Fine violet-blue iolites around 1 to 5 carats can range from $60 to $80 per carat, while stones of 5 to 10 carats can cost around $100 to $150. However, eye clean iolites of more than 8 carats are rare and can be more expensive. If you’re on a budget for blue gemstones, iolite will let you obtain the beauty of rarer and more expensive gems for a fraction of the price.

Is iolite enhanced or treated?

Iolite is commonly untreated and unenhanced, making it an attractive selling point for some buyers. Instead, its best color is shown through strategic cutting and polishing. Most gemstones are heated to enhance their color, but it’s said that iolite’s chemistry won’t allow it, as it cannot handle high temperatures. In other words, iolite cannot be enhanced.

Therefore, no treatments have been successfully used to alter its color or remove inclusions, so you can assume that the iolite you’re buying is untreated. With its affordability and natural blue and violet hues, many regard it as an underappreciated gemstone.

Is iolite a durable stone for jewelry?

On the Mohs scale of mineral hardness, iolite ranks at 7 to 7.5. However, it has a lower toughness rating due to its distinct cleavage in one direction. It’s a durable jewelry stone but is less durable than topazes, sapphires and diamonds. Iolite shouldn’t be worn at the gym, during strenuous activities, or in situations where it might be hit against hard objects. With reasonable care, you can wear iolite jewelry for decades.

What are the metals and gemstones that go well with iolite?

Iolite ring

Yellow gold iolite ring by Silver Capital. See it here.

Going for gold or silver is a personal choice, but iolite will look stunning with all metals used in jewelry. Yellow gold beautifully contrasts iolite’s vivid violet-blue color, while white gold, platinum and silver highlight its beautiful hue. Just be careful if the stone has a noticeable yellow tint, as it can be emphasized by yellow gold and rose gold metals.

If you love vintage styles, think of iolite earrings and necklaces in yellow gold. For a modern, trendy look, opt for iolite in white gold. Iolite and rose gold has a vintage look that’s quite unique and extremely distinct.

Iolite can be combined with other blue stones like topaz, as well as other colored gemstones like peridot, garnet, citrine, amethyst and even diamonds, for a multi-gemstone multi-colored look.

What are the iolite imitations to watch out for?

Iolite imitations aren’t common since the stone is inexpensive. In fact, it’s more often used as an imitation of tanzanite.

Usually, colored glass is used to imitate iolite but it’s easy to spot. Glass ranks around 5.5 to 7 on the Mohs scale, while iolite rates 7 to 7.5. This means that glass can be easily scratched, unlike iolite. Also, you can simply look for the depth of color and proper reflection of light.

What are the mystical properties of iolite?

The gemstone’s symbolic meaning and mystical properties are associated with its historical importance. Many historians believe that iolite was the “sun stone” used by Vikings for navigation at the sea. The legend has it that the Vikings navigated by the sun, and they used polarizing lenses and glare-reducers to locate the sun on cloudy days. With the help of iolite, Nordic mariners were able to know their location.

No wonder iolite has gained a reputation as a guidance stone, bringing clarity to the wearer about their dreams, journey and explorations. Many also opt for iolite jewelry to guide them on fulfilling their life’s purpose. The color of the gemstone is inviting and soothing, so it’s said to give hope during difficult times and promote tranquility and peace. In some cultures, it’s thought to help unlock creativity and aid sleep.

How do you clean and care for iolite?

Due to its cleavage, iolite should be protected from extreme heat and sharp blows that could break the stone. While warm, soapy water is always safe, you shouldn’t use steam or ultrasonic cleaners. Also, detergents, bleaches and other harsh cleaning products aren’t recommended. Since the gemstone isn’t commonly treated, you shouldn’t have to be concerned about dyes, fillers and coatings, as its color is stable. When handled with care, iolite jewelry will last a lifetime.

Does iolite jewelry makes perfect gift?

If you like the luxury appeal of tanzanite and sapphires, iolite can be an inexpensive alternative for jewelry gifts. Just opt for pieces with the stone in protective setting like bezel, which wraps the gem in metal, rather than prongs, which leave its sides exposed.

Whether or not it served as a navigation tool, history buffs will find iolite jewelry fascinating for its association with the Viking “sun stone.” Since it’s believed to have creative powers, it’s also a perfect gift for authors, artists, designers, architects, and anyone in the creative field.

It’s also thought to have healing powers for both physical and emotional aspects, making it a thoughtful present for one going through hardships in life.

Iolite might not be considered a birthstone, but it’s regarded as the traditional 21st wedding anniversary gemstone.

Wrapping Up

Iolite has been loved and valued by different cultures throughout history as a “sun stone” and healing stone, and it remains a powerful gemstone for mystics and intuitives. However, regardless of its metaphysical symbolism, iolite never fails to put on a spectacular display of optical effects, fascinating every gemstone lover. If you’re looking to add a splash of blue to your collection, iolite jewelry is a stunning and inexpensive choice!