I have heard that Tanzanite has been found in several other places besides Tanzania though I don’t recall where. I have a 3 carat triple A rated, gem quality Tanzanite in a pear shape. It is a beautiful clean stone with deep blues and flashes of red. I had it mounted in 14k gold and had it surrounded with VS2-S1 round diamonds. Being that Tanzanite is a softer gem on the mohs scale, I have it as a pendant for a necklace rather than a ring. But, I rarely wear it anymore. I had two 1.2 carat loose round Kanchanaburi sapphires made into earrings to match also with diamonds surrounding them. A different life....
No, Tanzanite is only found in Tanzania. . . in a specific area of Tanzania. The Government of Tanzania has split that area into four mining areas, Blocks A, B, C, and D.
In 1990, the Tanzanian government split the Tanzanite mines into four sections: Blocks A, B, C and D. Blocks A and C were awarded to large operators, while Blocks B and D were reserved for the local miners. In 2005 the government renewed the lease of Block C mine to Tanzanite One, who paid 40 million dollars for their lease and mining license.[citation needed] — Wikipedia
From Gemstone Facts: "Fact: There is only one region on earth where Tanzanites have been found, namely Tanzania."
You are right about the hardness of Tanzanite. . . it's about as hard as the hardest glass. It will wear less well than CZ which wears out in rings after a few years of stead wear. As such it should be considered only for cocktail ring use. A pendant is just fine. Your's sounds beautiful. My girlfriend has also has a 4 carat Tanzanite (mined from Block D, supposedly the best source) that was in a ring, and had it reset in a pendant along with her mother's Tanzanite of about the same size, with diamonds as well. It's gorgeous. They got them when Tanzanite was first released and quite inexpensive.