Amethyst vs Tanzanite — Blue and Purple Beauties

Last Updated on October 18, 2023 by Juli "Jewels" Church

Interested in the blue and purple shades of amethyst or tanzanite gemstones?

You're in the right place. It can be hard to choose between tanzanite vs amethyst — both gorgeous stones. Let's see if we can make it easier easier for you to decide. 

In this guide, you'll learn what you need to know to pick the jewel you really want, plus answers to questions like: 

Amethyst vs Tanzanite
  • Is tanzanite valuable?
  • Are there synthetic amethyst gems?
  • Does amethyst make a good engagement ring?

Main Differences Between Amethyst vs Tanzanite

The main differences between amethyst and tanzanite are:

  • Amethyst is a variety of quartz crystal, whereas tanzanite is part of the zoisite gemstone variety.
  • High quality amethyst is still affordable, whereas high quality tanzanite is more expensive.
  • Amethyst stones are typically shades of purple, whereas tanzanite stones can range between blue and purple.
  • Amethyst is found all over the world, tanzanite comes from only one location.
  • Amethyst can produce extremely large crystals, whereas tanzanite crystals don't get as big.

Amethyst vs Tanzanite Origin

Amethyst and tanzanite can both be classified as purple gemstones at first glance, but that's where the similarities stop. These two stones are varieties of completely different gemstone species. They have different chemical and physical properties. Let's learn more about where they come from.


Amethyst is one of the most popular gemstones sought after today. Whether they're looking for gorgeous purple jewelry or searching for crystal healing purposes, amethyst stones are in great demand.

credited to: Mauro Cateb

Amethyst is part of one of the largest gemstone species, quartz. Quartz is the most common mineral found within the earth. It's composed of oxygen and silicon. Amethyst is purple quartz. Quartz is also responsible for other favorite healing crystals like rose quartz, smoky quartz, and the November birthstone, citrine. 

Amethysts are the birthstone for the month of February and make great birthstone jewelry. In the same right, they also are perfect jewelry gifts for Valentine's Day.

These purple stones have a rich history. The use of amethyst crystals dates back to ancient civilizations. The Egyptians would craft carvings out of an amethyst gem into decorative pieces and as amulets of protection. The ancient Greeks believed amethyst prevented drunkenness . Amethyst crystals are available in large quantities and in big geodes. They are widely used as home decoration pieces as well as amethyst fine jewelry. 

Amethyst carving credited to: cobalt123

The most notable places for amethyst stones are Brazil, Uruguay, Russia, India, South Korea, and the various placed in the United States.


Tanzanite is the second most popular blue gemstone, with blue sapphire taking the lead. However, many tanzanite stones are purple in addition to the deep blue color. "Tanzanite" is the trade name for the blue-violet hues of the zoisite gemstone species.

tanzanite crystals

blue zoisite on calcite matrix credited by Robert M. Lavinsky

Tanzanite is my personal favorite colored gemstone, and it also happens to be the modern birthstone of my December baby.

These stones are some of the rarest gemstones, unlike amethyst. Tanzanite only comes from one location, the Merelani Hills in Northern Tanzania. Unlike amethyst, tanzanite doesn't have connections to ancient civilization. Zoisite had been around, but the tanzanite variety wasn't discovered until 1967.

Near Arusha, Tanzania, Maasai livestock herders discovered the blue zoisite crystals. However, credit was given the gold prospector they hired, Manuel d’Souza. He thought they were sapphire stones.

The famous ring designer brand Tiffany & Co. were the first to advertise blue zoisite as a rare alternative to sapphire. They opted out of using its mineral name and gave it the trade name of tanzanite.

tanzanite crystal credited to Orbital Joe 

When the tanzanite mines were regulated, they were split up into blocks: Block A-D. You might hear of D block tanzanites being better than others, but there's no difference between the output of gems from the different mines.


Both amethyst and tanzanite share a similar appearance with blue, violet, and purple hues. That is the main reason why people confuse them. However, there is a distinct difference between high quality tanzanite and amethyst.


An amethyst crystal colors can range from a light lilac or lavender purple to stunning deep purple hues. Iron impurities give amethyst its different shades of purple.

Top color amethyst stones are called Siberian color amethyst. Initially, Siberian amethyst came from Siberia, but the same colors found in these stones are found in other places of the world. Instead of describing origin, today Siberian amethyst refers to amethyst with distinct red and/or blue flashes beyond the purple body color in natural light.

You can also assume that all amethyst stones have not received heat treatment. Heat treated amethyst can turn the purple crystal into an yellow or orange colored stone. This is referred to as citrine, which can occur naturally but most on the market is actually heat treated amethyst.

Natural amethyst can be subjected to natural heat treatment within the earth. That's why amethyst and citrine are found growing together. The conditions in the earth can heat part or all of a purple amethyst, causing it become a bi-colored gemstone. The combination of the two create ametrine, another favorite gem of mine.

faceted ametrine stone Public Domain

Ametrine occurs naturally, but it's not common to see highly vivid deep purple and bright orange crystals . They've been heat-treated further. Ametrine stones make some of the most beautiful custom cut and fantasy cut gemstones.

Heat treatments can also be used to lighten the color of amethysts and turn them into different colors. You may hear of the trade name of "green amethyst", but gemologists call this prasiolite. It's distinguished as a different gemstone than a true amethyst.

Synthetics and Imitations

There are still synthetics and imitation stones for amethyst gems despite their abundance. Lab created amethyst are grown and can also be created using gamma rays on smoky quartz. You shouldn't expect to see lab grown amethyst jewelry at fine jewelry retailers. Mainly marketplaces like Etsy and Facebook have these synthetics.

Remember, synthetic amethysts are real amethysts just like most other lab grown versions of other colored gemstones. They have the same physical properties, chemical properties, and optical properties. Other amethyst imitations include purple cubic zirconia, purple glass, and plastic.


The color blue is usually the most dominant color in a tanzanite. It may or may not have purple secondary hues. It might surprise you to know that vivid color tanzanite occurs when zoisite has traces of vanadium in their crystals. They are heated at low temperatures to produce the gem quality tanzanite jewelry we see today.

Heat treatments can have an effect on cost and value of gems. Still, there are some heat treatments that are considered normal and accepted that don't have an impact. Tanzanite is one of the those stones. You should expect all jewelers to carry treated tanzanite jewelry. The treatment can't be altered by heat or other means.

Both tanzanite and amethyst have pleochroism. Under polarized light, the both tanzanite and amethyst can change color between hues of blue and purple shades.

Synthetics and Imitations

Tanzanite is one of the few popular gemstones that doesn't have a synthetic or lab-created alternative to its natural form. Instead, there are plenty of tanzanite imitations in the market. Tanzanite can be imitated by any blue or purple crystal or stone. Zoisite itself has a different specific gravity than true tanzanite, making easy for scientist to identify tanzanite from other crystals.

Tanzanite can be an imitation of sapphire and vice versa. Sapphires are precious stones, whereas tanzanite is a semi precious stone. Tanzanite may be rare, but sapphires are in higher demand. That is why tanzanite may be used as an imitation stone. Some shades of blue sapphire can produce violet color crystals.

Violet hued blue sapphire ring from Brilliant Earth

Other gem material used to imitate tanzanite is often glass, cubic zirconia, and amethyst stones more on the blue side.

Price and Value

It may be hard to distinguish an amethyst vs a tanzanite at first glance, but they differ hugely in price and value. Not surprisingly, a 1-carat amethyst stone is going to cost much less than a 1-carat tanzanite stone. 

amethyst engagement ring

Amethyst crystals can grow to giant sizes, especially in South America. Top color amethyst gemstones in larger carats are still relatively affordable. Amethyst isn't a stone worth investing in because of how abundant they are. 

Tanzanite is a relatively rare since it only comes from one source. However, the demand isn't high enough to make it a rare commodity. When it comes to gemstones, only top color ones tend to be worth anything. 

tanzanite engagement ring

Siberian amethyst costs between $50-100 per carat. Top color tanzanite stones may go for $500 per carat. 

loose tanzanite

Loose Pear Tanzanite from Brilliant Earth

hexagon cut loose amethyst

Loose Hexagon Cut Amethyst from Brilliant Earth

Choosing Between an Amethyst vs a Tanzanite

There are many reasons to love tanzanites and amethysts. If you're looking for a cost affordable stone you can get in large sizes, an amethyst ring may be right up your alley. 

If you're wanting a unique violet gemstone, tanzanite may be the way to go. Tanzanite rings aren't as durable as amethyst engagement rings for everyday day wear, but they still make beautiful jewelry pieces. 

If you're looking for best quality amethyst and tanzanite, I recommend checking out Brilliant Earth. It can be harder to find top quality semi-precious gemstones at fine jewelry stores and online. Brilliant Earth has a handful of loose amethyst and tanzanite stone to help you custom build your own ring online. 

Wear your amethyst jewelry more often, and your tanzanite rings on occasion. Low impact jewelry like tanzanite earrings and necklaces will wear down less than tanzanite rings.

At the end of the day, both of these gemstones are worth adding to your jewelry collection. But if you can only choose one, choose the one that best fits your lifestyle and budget. 

Meet Your Jewelry Expert

Learn More About Jewelry

Want to learn more about jewelry? Check out these other helpful resources written by our jewelry experts!