Iolite vs Tanzanite: What Are They, And What’s The Difference?

Iolite and Tanzanite are two stones that are often mistaken for one another.

Since there is so much confusion about the two stones, we took the time to conduct research into their similarities and differences.

You will find out how to correctly identify each stone.

Iolite vs Tanzanite (EXPLAINED)

What is Iolite?

Iolite is a grey, purple, light blue, dark blue, or colorless gem that is very durable.

It is abundant in iron with a transparent appearance and is a part of the cordierite mineral family.

We can see different colors in this stone when we hold it at different angles.

It is associated with the cosmos.

The name iolite comes from the Greek word for violet, “ios”.

India supplies most of the world’s Iolite stones.

However, miners also find it in countries such as Brazil, Tanzania, Norway, and Sri Lanka.

Miners collect this stone in abundance, so it is not rare.

It has a vitreous luster which means it has a reflective appearance reminiscent of glass.

This crystal is quite sensitive to heat.

You can safely clean these stones with warm (not hot) water and mild soap. 

Some iolite has earned the name of “water sapphire”.

This type of iolite displays two colors – a violet or blue hue in one direction and a yellow to colorless hue in the opposite one.

The ability to display a drastic color change in different directions is called pleochroism.

The crystals have a trichroic quality as up to three colors are seen based on the angle of view.

What Is Iolite Used For?

While you should always consult a doctor for medical care, this stone is believed to promote liver detoxification.

It is used to help grow nails and hair.

People use Iolite to help treat of malaria and other ailments that cause fever.

Some rely upon it for spiritual healing.

Its accessibility and abundance makes it an attractive option for folks who are interested in learning more and implementing crystal healing techniques.

Iodite is sometimes used as a substitute for sapphire.

Iodite has quite a long history.

The Vikings once used iodite for navigational purposes.

The stone was used to polarize light and earned the title of “Compass Stone”.

What is Tanzanite?

Tanzanite gets its name from the country of its origin, Tanzania.

All mines are located in a small area within the Merelani Hills near the base of Mt. Kilimanjaro.

It is the 2nd most popular blue gem in the world behind sapphire.

In contrast to iolite, Tanzanite was not discovered and sold commercially until the 1960s.

The world-renowned Tiffany’s helped make this recently discovered gem very sought after.

December babies may claim Tanzanite as a birthstone. 

It can come in hues such as violet, blue, gray, yellow, pink, and green.

It is composed of the mineral zoisite.

The presence of vanadium within the structure gives it a stunning blue color.

Tones and color saturations come in various blue ranges.

The most valuable ones range from vivid blue to violet-blue.

This gem is also trichroic.

The same Tanzanite gem may appear blue in one direction, purple in one, and red in another.

This color variation is beautiful.

However, gem cutters need to cut the crystal in such a way, that a vivid blue will be present from at least one angle.

The intense blue ones are the most valuable and closely resemble a sapphire.

What Is Tanzanite Used For?

Tanzanite is mostly used for various jewelry items such as pendants and earrings.

Its 6.5 hardness rating simply makes it too soft for ring stone or any other item that will often encounter some abrasion.

Jewelry that won’t have constant contact is best for this gem.

Similarities Between Tanzanite and Iolite

Both of these stunning gems share a range of violet or blue hues.

You can find both in Tanzanian mines.

Iolite and Tanzanite both share pleochroic qualities.

They both also fall into the trichroic category since they appear to be three different colors based on the view angle.

Many gem buyers often confuse the two gems due to their similar blue hues and pleochroic characteristics.

Differences Between Tanzanite and Iolite

Tanzanite is a softer stone than Iolite.

While both gems can be found in Tanzania, Tanzanite is mined ONLY in that country.

However, Iolite can be found in mines beyond Tanzania in places such as Brazil, Germany, India, Zimbabwe, Norway, and Sri Lanka.

Iolite has even been found in the state of Wyoming.

Iolite was way more abundant and affordable than Tanzanite.

Since Tanzanite is only mined in such a limited location, it is quite rare and more expensive. 

Due to its durability and long history, iolite has more uses.

Tanzanite was only discovered in the 1960s while iolite was a navigational resource for the Vikings.

How To Identify Iolite

While iolite has a luster reminiscent of glass, it is harder than glass.

Glass may also already be scratched.

On the other hand, iolite has a hardness score of 7 to 7.5.

Real iolite is very hard to scratch, so it is popular in jewelry like rings.

Cleavage refers to the tendency of crystals to break along a certain plane.

Iodite has perfect cleavage in one direction, so it can be a challenge to properly cut.

Focus on how the stone reflects different light, its deep blue hue, and test its trichroic features at three different angles.

How To Identify Tanzanite

Like iolite, you should view this gem from different angles to see color differences on different sides at the same time.

Remember it is pleochroic. 

Like rubies, tanzanite is double refractive.

Refraction is the angle that light bounces off an object.

Test for double refraction angles with a dichroscope.

Iolite and Tanzanite are both beautiful gemstones.

If you want a stunning blue gem possessing dynamic light and color effects, these two gems are great choices.

One gem, iolite, has more uses than the other.

However, Tanzanite is more valuable.

Now that you know more about these stones, you can feel more comfortable buying the gem that is ideal for you.

Iolite vs Tanzanite