The discovery of tanzanite

8.0 k views | By John Saul

Tanzanite was not discovered in the way many believe. Geologist JOHN SAUL tells the true story behind this mysterious deep-blue beauty.

Many accounts of the discovery of the alluring blue tanzanite have found their way into print, most of them quite misleading or simply wrong.

The stone, which was the first new gem of commercial importance since the discovery of alexandrite in April 1834, was found on July 7, 1967 by Manuel de Souza.

De Souza, known as Mad Manuel due to his overwhelming passion for prospecting in the African bush unarmed and on foot, began his prospecting adventures on the Lupa Goldfields of western Tanganyika, India in 1939. But when it became unprofitable to mine gold after World War II, he moved to Dar es Salaam.

As there were no minerals to seek in the coastal region, de Souza departed for the Shinyanga diamond fields but Tanzanian prospecting licences for diamonds were nearly impossible to get, due to the monopoly of the Williamson Diamond Mines.

Following a period in the region of Lake Victoria, de Souza moved to Arusha to try his luck in the Kilimanjaro area.

On Easter weekend in 1967, his feet got particularly itchy and he hired a pickup and driver to drop him and his equipment at a destination he had selected southeast of Arusha.

Not having anticipated how bad the roads were, the driver refused to go further than a village called Mtakuja, deep in Maasai country. There, tens of miles short of the agreed-upon destination, de Souza was unceremoniously off-loaded from the vehicle.

He didn't know it yet but such serendipity had brought him to a spot about four miles from the future tanzanite find.

Jump forward to June 7 when de Souza, accompanied by four men he had hired in Mtakuja for mere shillings a day, stumbled across a transparent blue stone sitting on the surface of the ground.

From its colour he thought it sapphire but dismissed this when he tested its hardness.

Back in Arusha, he consulted the only reference book on mineralogy in his possession and decided that olivine (also known as peridot) was the closest match to his stone.

He registered it as such on July 25, 1967 - a move prompted by the Tanzanian law that required prospectors to specify the minerals before registering a mining claim.

It did not take de Souza long to discover that the gem was not olivine, but he remained at a loss as to its actual identity. Some said it was dumortierite, others argued cordierite. Swahili-speaking prospectors fittingly-labelled it Skaiblu, meaning sky blue.

Around this time, de Souza sent samples to the Gemological Institute of America (GIA), perhaps the only lab with the equipment at the time to identify zoisite.

Ultimately, however, it was a Tanzanian government geologist named Ian McCloud who eventually identified the mysterious sky-blue gem as tanzanite, though the gem wasn't named until samples reached Tiffany and Company vice president Henry Platt.

Platt appreciated the beauty of the material and subsequently coined the name tanzanite, in reference to its country of origin.

De Souza died at age 56 on August 21, 1969, prompting the Northern News to run an August 29 proclaiming de Souza the "hero of the tanzanite rush". Yet, within a short time, fanciful versions of the tanzanite story began to circulate.

One is that Ally Juyuwatu made the find, but he and his then mining partner Alloys Anthony Duwe were quick to proclaim Manuel de Souza as the original discoverer.

Another was Habib Esmail, an erstwhile claim jumper in the employ of well-known Greek miner George Pappas. And yet another supposed discoverer is Jumanne Ngoma, a sometime employee of Esmail's.

An article in Life magazine in 1969 reported that de Souza was led to the find by a Maasai but this was rejected by Chief Soibhe, who had shared milk with de Souza at Naisinya manyatta in the traditional Maasai manner of signalling of acceptance. Notably, none of these alleged discoverers has ever come forth to seek compensation.

In the years following the discovery, de Souza received great attention. "European gem dealers soon learnt the true story and Manuel's discovery and his success swelled throughout Europe courtesy of social and factual magazines including Bunte (Jan 1969), Der Spiegel, Jasmine (July 1969), Time (Jan 1969) and Life (May 1969)," wrote son Angelo de Souza. "This was undoubtedly the most fulfilling and productive phase of his life. Manuel's prospecting ventures never stopped and his discoveries found their way to the attention of leading gemmologists of the time.

"While notoriety from European socialite magazines was welcome, it was the recognition of his find by such notable academics as Professor Strunz (Germany), Dr. Baker (Germany) and Dr. Saul (American based in Kenya) that meant the most to Manuel. Dr Saul, for instance, did a Fission Track Dating published in the American Mineralogist that Tanzanite could be 550 million years old. It was the importance of these data linking his name to a gem crystallised hundreds of millions of years ago that made all the failings he endured on his journey worthwhile."

Manuel's children and other members of his family are now scattered all over the world in Tanzania, Denmark, Malta and the United Kingdom. The house where he lived is now the residence of the Bishop of the Diocese of Mount Kilimanjaro.

These days, the tin roofs and electric lights of the tanzanite mines are visible from the right-hand side of planes landing from the west at Kilimanjaro International Airport. Whether they recognize what they are glimpsing or not, the tanzanite mines are the first thing that many early-morning tourists arriving from Europe see of Tanzania.

About the author: John Saul is a geologist and founding member of International Colored Gemstone Association. He also discovered and owned the famous John Saul Ruby Mine in Kenya. This article first appeared in the Spring/summer issue of InColor - the official publication of the International Colored Gemstone Association.

Posted July 01, 2008