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Cordierite Gemstone: Properties, Meanings, Value & More

コーディエライトの宝石：特性、意味、価値など

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Cordierite (pronounced kawr-dee-uh-rayte) is a blue to violet crystal as beautiful as it is lucky. It’s also one of the strongest pleochroic minerals to exist. In other words, cordierite displays different colors depending on what angle you look at it. 

When the mineral is transparent, and of high-clarity, cordierite is used as a gemstone called iolite. Does that mean cordierite is the same as iolite? Pretty much! But for the sake of this guide, we’ll stick to calling it cordierite. 

The cordierite gemstone meaning is one of guidance and clarity. It’s known as the “Viking’s Compass,” helping you physically and spiritually transport from one realm into another. Metaphysical vacay, anyone?

Ready to learn more about this dazzling, blue guiding stone? Join us as we break down all there is to know about cordierite in our Cordierite Gemstone Guide! 

About Cordierite Stone

The blue, pleochroic semi-precious gemstone has a few common pseudonyms:

• Iolite (Greek for violet)

• New Zealand blue quartz

• Dichroite (Greek for two-colored rock)

• Steinheilite (honoring Count Fabian Gotthard von Steinheil, former Governor General of Finland)

• Water sapphire (most common nickname; refers to cordierite’s ability to appear blue from one angle and clear as water from another) 

Unlike sapphire, cordierite isn’t usually treated to improve its appearance. More importantly, it’s less expensive. In fact, it’s often used as a substitute for sapphire or tanzanite. 

As a result, cordierite is a budget-friendly, alternative zodiac stone for Taurus babies. It’s also the traditional stone for Sagittarius. 

Got success in your eyesight? As a star stone for Saturn, cordierite enables go-getters to overcome distractions and hone in on their goals. 

You’ll want to flourish in love as you do in your career, right? Cordierite is the traditional gemstone honoring a 21st wedding anniversary and a less expensive alternative to sapphires for a 45th anniversary.

Now let’s master how to identify cordierite! 

Cordierite Mineral Specifications & Characteristics

It’s easy to confuse cordierite with other gems like quartz or amethyst. Its crystal structure is also very similar to beryl. In fact, its dimorph, indialite, has the same crystal structure as beryl. 

While it might resemble other gems at first, a closer look unveils some key differences.

For starters, cordierite is a strongly pleochroic mineral. Therefore, its colors vary when viewed from different angles. It’s one of the few minerals exhibiting such strong pleochroism and is the most well-known for displaying this optical property. 

When cordierite grows without obstructions, it forms short prismatic crystals with rectangular, cluster-like cross-sections.

Twinning can resemble plagioclase, but cordierite thin section may stain, distinguishing it from feldspars. Twins are more likely to occur from high-grade metamorphic rocks than medium-grade rocks.

Here’s an overview of cordierite’s mineral data:

• Cordierite formula: (Mg,Fe)2Al3(AlSi5O18)

• Mineral family: Crystosilicates

• Composition: Magnesium, aluminum, silicon, oxygen

• Mohs hardness: 7 to 7.5

• Color: Gray, blue, bluish-violet, greenish, yellowish-brown; colorless to very light blue in transmitted light.

• Crystal structure: Orthorhombic

• Luster: Vitreous (glassy)

• Transparency: Transparent to translucent

• Refractive index: 1.55 to 1.62

• Density: 2.55 to 2.75

• Tenacity: Brittle

• Cleavage: {100} Imperfect/Fair; {001} Fair; {010} Poor

• Fracture: Subconchoidal 

• Streak: White

• Luminescence: Non-fluorescent

• Pleochroism: Present, often strong; Violet gems tend to produce light violet or dark yellow hues. Blue gems tend to produce yellow to colorless hues.

Moving on, how did we come to know cordierite to begin with?

Cordierite History 

Cordierite was officially discovered in 1813 in Níjar, Almería (Spain). The mineral’s name pays homage to Pierre Louis Cordier, a French geologist and mining engineer credited with first studying the species. He described it in 1809 under the name of “dichroite.”

Remember earlier when we referred to cordierite as the “Viking’s Compass”? The name originates from an old Viking legend. According to the legend, Vikings used the pleochroic gems to navigate the seas on their voyages. The cordierite acted as a polarizing filter allowing sailors to gauge the sun’s proximity on cloudy days. Whichever side of the gem remained lighter indicated the location of the sun’s axis. 

What do we use cordierite for today? The mineral has few industrial uses. It used to be a common material for making catalytic converters. However, synthetic alternatives have since retired it for some time. 

Today it’s mainly used for making kiln shelves (usually for bread or pizza ovens). Cordierite is a natural stone that’s thermal shock resistant, meaning you can take it from low temperatures to very high ones without the risk of cracking. It’s also non-stick, heats up fast, and absorbs excess moisture. The result? A perfectly-cooked pie.

Anyone else hungry? Maybe exploring cordierite's metaphysical abilities will take our minds off our appetites. 

Cordierite Healing Properties

Most crystals can be used as healing stones to support the mind, body, and spirit in various ways. Cordierite is no exception.

Like other blue gemstones, cordierite often associates with stability, clarity, and calmness. This “compass stone” is believed to guide your physical, emotional, and spiritual body in the direction that best serves you and your goals. 

Here’s how cordierite can help steer you in the right direction. 

Physical Healing

Suffer from headaches? Memory not as sharp? Just not feeling 100%?

Cordierite is a go-to gem for various physical ailments: insomnia, body aches, stress, digestion, poor vision, mental decline, and even hair loss — keeping this gem close may keep your body and all its moving parts functioning at their very best. 

Emotionally, what is cordierite used for?

Emotional Healing

Cordierite stabilizes your emotions just as it does your physical body. It calms the mind making way for creativity, problem-solving, and decision-making. This crystal removes all hesitations and distractions from the mind — allowing you to analyze your goals and take clear action towards achieving them. 

Next time you find yourself at a crossroads, try meditating with cordierite to clear the mind and hone in on your end-game. 

Spiritual Healing 

Ever felt like you had a sixth sense? Cordierite’s spiritual meaning is all about making the impossible possible. 

If you’ve ever felt like you had an extraordinary ability (like clairvoyance) that you didn’t know how to tap into — cordierite just might be the key to awakening your natural, psychic gift. 

Cordierite is also a chakra stone used for activating your third eye chakra. This energy point is responsible for your perception, awareness, and spiritual connection. By opening your third eye, you open the door to your spiritual self. 

Before you harness all of its good vibes, you’ll need to know what qualities to look for when shopping for cordierite. Next up, grading!

Cordierite Gemstone Properties

Every gem has characteristics that help experts determine its market value. Knowing which ones apply to your stone can help you narrow down the best gem for your buck.

For cordierite, experts base value on the standard 4 Cs: color, cut, clarity, and carat weight.

Color

The most common cordierite color is blue to violet with matte glints. However, some three-color variations can appear blue, purple, and yellow. 

The gem is renowned for its pleochroism. When viewed from one angle, it shows a transparent blue-violet hue; when viewed from another, it appears grayish or yellow.

While color variation certainly matters, gems with stronger pleochroism tend to be more sought-after and, thus, more valued.

Cut

Cordierite’s hardness allows it to be faceted with ease. You’ll often see it in popular gemstone shapes like pear, oval, and trillion cuts.  

Cabochons and cordierite beads are also very popular. 

Since technically, iolite is gem-quality cordierite, you’re more likely to find cordierite sold rough (or uncut). Generally, rough gems tend to be the most affordable option. 

Clarity

Cordierite can contain any number of minerals as inclusions, such as hematite or goethite. These inclusions add color variations and give rise to burn marks around included grains, sometimes appearing as brown rings or pleochroic halos.

While inclusions may be present, they are usually minimal, having little effect on price. 

Carat Weight & Size

Cordierite is a fairly abundant mineral, but gem-quality crystals of higher carats are hard to come by. Most stones are two carats or smaller and tend to display the best colors. Anything over five carats with good clarity is rare and, therefore, more expensive.

Fun fact: The biggest cordierite specimen is on display in the British Museum and weighs 855 carats! 

Before cordierite ever makes it to grading, it has to be extracted. So what rocks contain cordierite? 

Cordierite Formation & Sources

Most cordierite forms during regional metamorphism of shales and other argillaceous (clay-like) rocks — usually in foliated metamorphic rocks (like schists or gneisses).

Less often, cordierite forms during contact metamorphism within hornfels (non-foliated, fine-grained metamorphic rock). It can also be an accessory mineral inside granite rocks and pegmatites (igneous rock formed during the final crystallization stage of magma).

Mining Locations

Within the United States, the most notable localities are found in New England. However, you can find cordierite mines scattered throughout the globe. 

Other notable localities include:

• Brazil

• Canada

• Finland

• Germany

• India

• Japan

• Madagascar

• Myanmar

• Norway

• Russia

• Sri Lanka

• Tanzania

• United Kingdom
  

…just to name a few!

Planning to add cordierite crystals to your collection? Here’s how you’ll need to budget for your new gem.

Cordierite Price & Value

In terms of cost, cordierite makes for a much more affordable blue gemstone than some of its counterparts. While its abundance makes it less expensive, gem-quality iolite isn’t as easy to find — thus, fetching higher prices. However, if you’ve got your heart set on snagging some cordierite of your own, you have plenty of options that can accommodate any budget.

Rough cordierite, which tends to be the most affordable and common way that the mineral is sold, costs anywhere between $0.08 per gram for lower-quality stones to $2.09 per gram for higher-end specimens. 

The price of cordierite carvings can vary depending on size and intricacy. They generally run between $30 and $130. 

Faceted cordierite typically ranges between $0.45 to $3.90 per carat, depending on quality. Higher-end gems can fluctuate between $30 to $60 per carat. 

Cordierite cabochons usually cost around $1.30 to $2 per carat. Higher-end pieces can start at around $11 per carat. 

Even though cordierite is an abundant resource, you rarely see it seen in mass-merchant jewelry. When you find cordierite jewelry, prices tend to vary depending on gem-quality and what kinds of metal are used. 

For cordierite jewelry, prices are generally as follows:

• Rings — as low as $13 or as high as $1900 for fine jewelry

• Pendants — $30 to $130; as low as $11 or as high as $1700 for fine jewelry

• Bracelets — between $18 and $103; as low as $8 or as high as $350

Finally, let’s wrap up with the best ways to care for your cordierite.

Cordierite Care and Maintenance

Cordierite is a crystal that doesn’t require intense gemstone care. There are just a few key things to remember.

When cleaning your crystals, use lukewarm water, gentle soap, and a soft-bristled brush. It’s important to remember that prolonged water can crack cordierite, so try to be quick.

Cordierite’s hardness makes it durable enough for many uses. However, its main disadvantage is its distinct cleavage in one direction. This makes cordierite vulnerable to breakage when used in rings or other impact-prone items, so protective settings are always recommended. 

Avoid your cordierite coming into contact with:

• Harsh chemicals

• Perfumes & cosmetics

• Ultrasonic cleaners

• Steam cleaners

• Abrasive minerals

• Sudden temperature changes

For safekeeping, store your cordierite in a soft, fabric-lined box or fabric pouch separate from other gems to prevent damage from impact with harder minerals. 

Captivated by Cordierite?

Vikings? Epic transformation? What more could you ask for from a crystal? In addition to its alluring pleochroism and eye-catching hues, a little cordierite may just be what you’ve needed to shift you back in the right direction. 

After all, it worked for the Vikings. Why not you?

Buy cordierite and other gemstones today!