Tanzanite

           Few travelers arrive in Tanzania without having heard the magic word "TANZANITE".  It's a one-of-a-kind gemstone found in the Massai country of Tanzania, right in sight of Mount Kilimanjaro.  By nature, tanzanite is trichroic, meaning that it shows different colors, depending on the direction in which it is viewed.  The most common natural colors are blue, violet and salmon, caused by traces of the element vanadium in the crystal structure, but other colors do occur in odd corners of the deposit where traces of other metals may partly replace the vanadium.
           Most tanzanite is heated before it reaches the market.  This worthwhile procedure is entirely legitimate, and was begun by the first generation of tanzanite miners who put their stones into charcoal fires in order to improve their color.  The effect is to turn the "salmon axis" to blue/purple without affecting the other two axes.  ("Salmon axis" has been put in quote marks here because it is actually commonly colored pink, grey, yellow or otherwise with the "salmon" aspect left to the viewer's imagination.)

           Tanzanite is a variety of the mineral zoisite, named after Siegmund Zois, Baron von Edelstein (1747-1819), an Austrian scholar who financed mineral-collecting expeditions.  Within a year or two of Manuel de Souza's initial discovery in Tanzania, Tiffanys came up with the name "Tanzanite".  In those days, a new name was badly needed for it was a period during which German and Swiss gemstone dealers were very active in East Africa and they claimed that a new name was required because the German pronunciation of the "zoisite" sounded much like the English "suicide".  The truth of the matter is actually far more interesting and goes back to the initial discovery of the tanzanite deposit by Manuel de Souza

De Souza purchase By late 1967, Manuel de Souza, the discoverer of the tanzanite deposit knew that his initial identification as the mineral olivine (peridot) was incorrect but “dumortierite”, his second guess was also wrong.  The correct identification of the mineral as “zoisite” was made shortly after by Ian McCloud, a Tanzanian government geologist in Dodoma, at Harvard and at the University of Heidelberg.

           De Souza. was a tailor in Arusha whose family originated from Goa, formerly part of Portuguese India.  In Tanzania, he earned his living by making uniforms for the army but he had the "prospecting bug" and all his spare time and money were spent in looking for minerals.  His passion probably started with gold-panning in western Tanzania, but in short order he realized what all East African prospectors come to understand, namely, that the countryside hides a rich and unexpected stock of mineral wealth.  Gold is not all that to be found. There are many surprises and the biggest occurred on DATE when de Souza discovered what was to become the world's only tanzanite mining region.

           A problem which caused much confusion but little harm was that Manuel had no idea what it was that he had discovered.  Further, "zoisite" was the very last mineral name that would have come to mind because of the widespread belief in East Africa that zoisite had to be bright green as at Longido, somewhat further to the north in Tanzania.  In truth, zoisite is usually gray, dirty white or dull greenish or brown… "rock colored".  But in Tanzania, a bright green non-gem (opaque) variety with traces of chromium was known far and wide.  (In Lexviken, Norway, by contrast, where a non-gem variety colored by traces of manganese is known, people are likely to associate zoisite with the color pink, "manganese pink".)
 
           But Manuel and his family found themselves with a splendid blue-purple-"salmon" colored transparent gemstone.  What was it?  The question was important to him because he had to register his mining claim at the government Mines & Geology Department and to do so, he needed a mineral name, even a provisional name.  In short order, he came up with the incorrect identification "olivine" and as other prospectors pegged the surrounding countryside around his original discovery site, they came up with other incorrect names "cordierite", "epidote", "dumortierite", etc. Not long afterwards one of the Tanzanian government geologists came up with the correct identification of "zoisite", though many people continued to harbor doubts until confirmations cam in from Harvard, the British Museum and Heidelberg.

           Thus it came about that other people had registered mining claims for the mineral "zoisite" before Manuel de Souza himself got around to changing the name on his original claim registration. During this period another name became popular, a lovely name whose disappearance we regret.  This was "Skaiblu", a Swahili-language borrowing of the English "Sky Blue".

           Zoisite, Tanzanite or Skaiblu, this is a lovely stone.

Eldot and Co Cutting charges addressed to our grandfather, a Vice-president at Saks Fifth Avenue in New York.  The largest stone weighed over 40 carats and was a fine blue	Sak’s Fifth Avenue This was a valuation of our grandmother’s tanzanite ring.  We are not sure if the rectangles which show through the paper were mining claims of the plan of a house.

Zoisite claim Map Part of a document used in pegging tanzanite claims.	Prospection rights This was renewed at the time of the “tanzanite rush” but Dad had not maintained his Tanzanian residency.

Smithsonian letter Paul Desautels became a friend.  A couple of years later he arranged a dinner for our father and some other gemologists inside the gem room of the Smithsonian.	Smithsonian invoice Early transaction with the Smithsonian.

Export to Idar Ten pounds of fine blue tanzanite!

Other purchase Tanzanite was smuggled into Kenya and sold by people with mining claims who claimed that it was Kenyan production.  Very dark blue gem tanzanite was actually found in southern Kenya in later years but the cuttable fragments were rarely larger than half the diameter of pencil.

Life Magazine There was intense rivalry among those who owned claims for tanzanite in the later 1960s.	Eric Saul and Patrick Voillot making a 55 minute documentary on tanzanite for French TV.  The picture with the poor lighting was taken underground.