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 Tanzanite is noted for its remarkably strong trichroism, appearing alternately sapphire blue, violet and burgundy depending on crystal orientation. Tanzanite can also appear differently when viewed under alternate lighting conditions. The blues appear more evident when subjected to fluorescent light and the violet hues can be seen readily when viewed under incandescent illumination. Tanzanite is usually a reddish brown in its rough state, requiring artificial heat treatment to bring out the blue violet of the stone. The mineral was named by Tiffany & Co. after Tanzania, the country in which it was discovered. Emmanuel Merishiek Mollel, a Maasai tailor and part-time gold prospector living in Arusha (Tanzania), found transparent fragments of vivid blue and blue-purple gem crystals on a ridge near Mererani, some 40 km Southeast of Arusha. He decided that the mineral was olivine (peridot) but quickly realised that it was not, so he took to calling it "dumortierite", a blue non-gem mineral. Scientifically called "blue zoisite" , the gemstone was renamed as tanzanite by Tiffany & Co., who wanted to capitalize on the rarity and single location of the gem, but who thought that "blue zoisite" (which might be pronounced like "blue suicide") wouldn't sell well. Tiffanys original campaign advertised that tanzanite could now be found in two places "in Tanzania and at Tiffany's". The normal primary and secondary hues in tanzanite are blue and violet. Tanzanite is a trichroic gemstone, meaning that light that enters the stone is divided into three sections, each containing a portion of the visible spectrum. After heating, tanzanite becomes dichroic. The dichroic colors are purple and blue. The hue range of tanzanite is blue-purple to purple-blue.
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