Tanzanite Mining in Africa: VOC Gems’ Expedition 650 Meters Underground
Natural tanzanite is one of the most remarkable gemstones discovered in modern times. It is prized for its rich blue-violet color and its striking pleochroism – the ability to display different hues, ranging from deep blue to violet and purple, depending on the viewing angle.
To understand the true nature of this extraordinary gemstone, the VOC Gems team traveled to Africa, to the foothills of the snow-capped Mount Kilimanjaro. Our mission was clear: to descend into the legendary Merelani mines.
Merelani is the only place on Earth where tanzanite is found. There is no second source, no alternative deposit anywhere else in the world.
This video offers a rare opportunity to witness the complete journey of a gemstone – from the depths of the earth to the hands of a collector.
The Story of “Blue Gold”: From an Unfortunate Name to Tiffany’s Marketing Triumph
From a mineralogical perspective, tanzanite is simply the blue variety of zoisite. When the gemstone was first discovered in Tanzania in the late 1960s, scientists referred to it as “blue zoisite.”
However, the renowned jewelry house Tiffany & Co., which took responsibility for introducing the stone to the American market, believed the name had little commercial appeal. In English, the word “zoisite” sounded uncomfortably similar to “suicide.” The marketing team quickly realized that a gemstone associated with such a word would face an uphill battle.
Instead, they gave the stone a new name inspired by its country of origin – Tanzanite.
Today, the market is filled with tanzanite offerings, yet few buyers ever consider how these gemstones are actually extracted from the earth. We traveled to Tanzania to follow the entire route ourselves—from the tourist shops of Zanzibar, where questionable sales tactics often target visitors, to the rough gemstone markets of Arusha, and ultimately to the restricted mining area of Merelani itself.
The Depth Test: 650 Meters Down on a Steel Cable
Gaining access to a working local mining operation required extensive approvals and coordination.
Merelani is a highly secured mining district surrounded by protective walls, where extraction takes place under extremely demanding conditions. We were not merely allowed to observe the process from above. The founder of VOC Gems and our team personally descended 650 meters underground, experiencing firsthand what can only be described as a true initiation into the world of mining.
This is not a tourist attraction equipped with modern elevators and comfortable walkways. The descent is made in a cramped metal bucket-like cage suspended by a single steel cable.
As you are lowered into complete darkness, the shaft narrows around you. The temperature rises steadily due to the surrounding rock, and breathing becomes increasingly difficult. At such depths, time is measured not in hours but in each breath of the heavy underground air.
“When you’re hanging on a worn steel cable above a half-kilometer vertical drop, surrounded only by darkness, humidity, and the distant sound of generators, your perception of reality changes completely. You see miners spending twelve-hour shifts in intense heat, sharing a single bottle of drinking water among four men. After witnessing that, it’s impossible to look at tanzanite as just another gemstone in a display case.”
– Founder of VOC Gems
How Tanzanite Selection Really Works: Filtering Out Low-Quality Material and Tourist Traps
Our descent into the mine revealed the unfiltered reality behind the jewelry industry.
Mining here is carried out both in open pits and underground tunnels that follow the gemstone-bearing veins deep into the rock. Miners use jackhammers and hand tools to break the surrounding stone, relying heavily on experience, persistence, and a measure of luck.
Yet discovering a crystal is only half the story.
As gemstone dealers, we wanted to understand what happens next—how rough production is sorted, traded, and ultimately selected for the international market.
In Zanzibar’s tourist shops, visitors are often offered poorly cut tanzanites at heavily inflated prices. Sellers frequently present average-quality material as exceptional gemstones, relying on the fact that most tourists lack the expertise to evaluate what they are buying.
True gemstone selection does not happen there.
It takes place much closer to the source, where experience, gemological knowledge, and direct access to the mining network make all the difference.
Having studied the entire supply chain firsthand, we can confidently say that the best opportunities to source exceptional tanzanites at fair market prices exist not in tourist shops, but on the professional wholesale gemstone market in Arusha.
This is where serious gemstone selection takes place.
By filtering through vast quantities of pale, included, and fractured material, we identify the rare few crystals that possess the qualities serious collectors seek: deep, naturally saturated violet-blue color, exceptional transparency, and outstanding clarity.
From the Depths of Africa to the VOC Gems Collection
We undertook this demanding journey ourselves to oversee every stage of the process – from the mine to the cutting table and ultimately to the collector.
When you hold one of these gemstones in your hands, remember that its beauty represents far more than color and brilliance. Behind every exceptional tanzanite lies the strength of the steel cables of Merelani, the endurance of African miners working deep underground, and the uncompromising gemological standards of the VOC Gems team.
Watch our detailed video report from Tanzania and discover the hidden journey behind one of the world’s most extraordinary gemstones.