Tanzanite: The Gemstone of a Generation - The Complete Guide (2025)


Discover the fascinating world of tanzanite - an exceptional gemstone that has only one deposit in the world. Šárka Bencová, a gemstone expert from the family-owned jewelry store Benc Klenoty, will tell you everything about this rare stone, which they call "the gemstone of a generation."

Tanzanite is a unique blue to purple gemstone that was only discovered in 1967 and is still mined in only one small area at the foot of Mount Kilimanjaro in Tanzania. After 15 years of working with gemstones, I can say that tanzanite is one of the most remarkable discoveries of the 20th century. Tiffany & Co. even declared it "the most beautiful stone discovered in the last 2000 years."

In this complete guide, you'll learn everything about tanzanite - from its geological origins to its properties and value to its investment potential. As a gemologist, I'll provide you with practical advice that I've gained from years of working with these exceptional stones.

📋 Article content:

🗻 Origin and discovery of tanzanite {#origin-discovery}

Geological origin

Tanzanite was formed approximately 585 million years ago under very unique geological conditions in the East African Rift Valley. It is a variety of the mineral zoisite, which was exposed to high temperatures and pressures in the presence of vanadium, which gives tanzanite its characteristic blue-violet color.

The story of discovery

In 1967, tanzanite was accidentally discovered by Maasai herdsman Manuel De Souza while walking near the village of Mtakuja, just four miles from where his driver had dropped him off. He initially thought he had found sapphires, but after testing the hardness, he ruled that out.

Dr. John Saul, a geologist from Nairobi who studied the stone, along with his father Hyman Saul of Saks Fifth Avenue in New York, helped correctly identify the stone as a variety of zoisite. Tiffany & Co. named the stone "tanzanite" in honor of Tanzania, its country of origin.

The uniqueness of the site

Tanzanite is found only in an area approximately 7 km long and 2 km wide in the Mererani Hills near the base of Mount Kilimanjaro. This rarity makes tanzanite at least 1,000 times rarer than diamond.

💡 Advice from a gemologist: "I have seen many rare stones in my practice, but tanzanite is truly exceptional. Its geology is so specific that it occurs in only one place on Earth - this makes it a truly unique gemstone."

💎 Unique properties of tanzanite {#properties}

Pleochroism - tricolority

Tanzanite is a pleochroic gemstone, meaning that it shows different colors - blue, purple, and burgundy - when viewed from different angles. The blue tones are more pronounced under fluorescent lighting, while the purple hues are better visible under incandescent lighting.

Physical properties

  • Hardness: 6.5-7 on the Mohs scale
  • Specific gravity: 3.35-3.55
  • Refractive index: 1.691-1.700
  • Crystal system: Orthorhombic

Heat treatment

In its natural state, tanzanite is reddish brown to clear in color and requires heat treatment to remove the brownish "veil" and enhance the blue-violet color. When heated to 600°C for approximately 30 minutes, the oxidation state of vanadium changes, causing or enhancing the blue color.

📊 Tanzanite quality rating {#quality}

As with diamonds, the quality of tanzanite is rated according to the 4Cs, but with some specifics:

1. Color - The most important factor

The most valuable are tanzanites with an intense, rich blue-violet or violet-blue color.

Color scale:

  • AAA quality: Deep blue-purple color, highest value
  • AA quality: Rich color with a slightly lighter tone
  • And quality: Medium color saturation
  • Commercial quality: Light tones with less saturation

2. Clarity

The highest quality tanzanite exhibits exceptional transparency, allowing light to pass through the stone unhindered. Visible inclusions reduce the value of tanzanite, especially in lighter stones.

3. Cut

The pleochroism of tanzanite requires careful consideration during cutting to enhance its play of color. Tanzanite is available in a wide range of shapes, but oval and cushion cuts are the most common.

4. Weight (Carats)

Unlike diamonds, the weight of tanzanite does not have as significant an impact on price as it does with other gemstones.

💡 Gemologist's advice: "When choosing tanzanite, focus primarily on color. An intense blue-violet tanzanite of a smaller size will have a higher value than a larger stone with a pale color. A quality cut is key to highlighting pleochroic properties."

💰 Prices and value of tanzanite {#price-value}

Current price range (2025)

For richly colored AAA quality tanzanite: 1 carat is approximately worth 200-350 USD per carat, 2 carat sizes reach 400-550 USD per carat, 3 carats and more reach 500-675 USD per carat.

Price categories according to quality:

  • AAA quality (1-2 ct): 200-550 USD/ct (5,000-14,000 CZK/ct)
  • AA quality (1-2 ct): 150-350 USD/ct (3,800-9,000 CZK/ct)
  • A quality (1-2 ct): 100-200 USD/ct (2,500-5,100 CZK/ct)
  • Commercial quality: 50-100 USD/ct (1,300-2,500 CZK/ct)

Impact of the pandemic on prices

Tanzanite prices are still down 20-30% due to the global pandemic. There is still time to take advantage of this situation as prices are expected to rise to new highs.

Factors affecting the price:

  1. Geographical uniqueness - only one site in the world
  2. Limited supplies - expected to be depleted within 20-25 years
  3. Growing demand - especially from China and India
  4. Processing quality - heat treatment vs. natural color

📈 Investment potential of tanzanite {#investment}

Why is tanzanite called the "gem of a generation"?

We are living during what has become known as the 'Tanzanite Generation' - those lucky enough to already own tanzanite, and those who acquire it in the next decade or so, will be the only ones able to purchase stones from the primary market.

Arguments for investment:

  1. Limited reserves: Total tanzanite reserves are estimated at 109 million carats, with the largest Block C site expected to last until 2040
  2. Growing Demand: China is showing more interest in tanzanite and with a huge market in China, growing demand could have dramatic effects on the price
  3. Historical comparison: Paraiba tourmaline was found in Brazil in the 1980s and mined until the mid-1990s. Today it can fetch up to $20,000 per carat

Arguments against investment:

Investing in tanzanite is fraught with danger. Counterfeits and imitations are common, making eBay and Facebook problematic for both sellers and buyers.

Investment recommendation:

  • Focus on AAA quality with intense color
  • Buy only with certification from recognized laboratories (GIA, GÜBELIN)
  • Larger stones (2+ carats) have better investment potential
  • Avoid impulse purchases without checking the quality

💡 Advice from a gemologist: "I recommend tanzanite as an investment only to those who understand the gemstone market. It is more of a long-term investment for stone lovers than a quick way to get rich. The most important thing is to buy a quality stone with proper documentation."

🧼 Tanzanite Care {#oven}

Basic care

Although tanzanite may have a hardness of 6-7, its tendency to chip and brittleness pose risks for everyday wear. Reserve these gemstones for occasional wear or use protective settings.

Cleaning:

  • Clean only with a soft brush, mild detergent and lukewarm water
  • Avoid ultrasonic cleaners
  • Do not use harsh chemicals.

Storage:

  • Store separately from harder gemstones
  • Avoid abnormal temperatures or sudden temperature changes
  • Use a soft case or velvet compartment

Suitable use:

  • Earrings and pendants - ideal for everyday wear
  • Rings - suitable for casual wear
  • Necklaces - safe for frequent use

⚖️ Tanzanite vs other gemstones {#comparison}

Tanzanite vs Sapphire

Property Tanzanite Sapphire
Hardness 6.5-7 9
Rarity Extremely rare Rare
Color Blue-purple All colors
Pleochroism Strong Weak/none
Price/carat $200-675 $500-5000+

Tanzanite vs Diamond

While tanzanite and diamonds are both valuable, their stories are very different. Diamonds are not subject to the rarity that tanzanite faces. While both stones are mined, diamonds can be grown in laboratories and are found all over the world rather than in one country.

The uniqueness of tanzanite:

  • Only one site in the world
  • Strong pleochroism
  • Limited life of mines
  • Heat treatment to improve color

🏪 Where to buy tanzanite {#buy}

Trusted sources:

  1. Certified jewelers with a gemologist

    • Expert quality assessment
    • Guaranteed authenticity
    • Long-term support

  2. Specialized companies for colored gemstones

    • Wider selection of qualities
    • Expert knowledge about tanzanite
    • Often direct contacts with miners

  3. Auction halls (for investment pieces)

    • Rare and exceptional stones
    • Documented provenance
    • Expert evaluation

What to watch out for:

  • Always request a certificate from GIA, GÜBELIN or another recognized laboratory
  • Be careful with online marketplaces without physical inspection options
  • Avoid "too good to be true" offers
  • Check the seller's reputation

In our workshop:

As a gemstone specialist, I offer:

  • Help choosing the right stone for your budget
  • Design and production of original jewelry with tanzanite
  • Long-term consulting and service
  • Consultation on the properties and care of tanzanite

🎯 Conclusion

Tanzanite is a truly exceptional gemstone that combines rarity, beauty and a fascinating geological story. As a "once-in-a-generation gem", it represents a unique opportunity to own something that will no longer be available to future generations.

Key findings:

  • Tanzanite is 1000 times rarer than diamond
  • Its blue-violet color and pleochroism make it unique
  • The investment potential is high, but requires expertise
  • Quality is key - focus on color and certification
  • Caring for tanzanite requires caution due to its fragility.

My advice: If you are fascinated by tanzanite, act wisely, but don't hesitate too long. These "windows of opportunity" close with each stone mined. Invest in quality, not quantity, and always have your stone professionally appraised.

💎 Do you need advice on choosing tanzanite?

As a gemologist with 15 years of experience and a specialist in rare gemstones, I will be happy to advise you on choosing tanzanite for your collection or piece of jewelry. In our workshop Benc Klenoty you can:

  • Consult with a gemstone specialist about choosing tanzanite
  • Browse our collection of rare colored gemstones
  • Design and make original custom jewelry
  • Get long-term advice for caring for your gemstones

📞 Call 604 574 388 or visit our workshop in Nové Město na Moravě.

Because rarity deserves expertise. 💎

The article was written by Šárka Bencová, a certified gemologist and gemstone expert from Benc Klenoty - a family-owned jewelry store with a tradition since 1928. We specialize in rare colored gemstones and handmade original jewelry.

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