Tanzanite 10mmIntense violet to blue colors throughout this gemstone. Tanzanite's only known source in the world is a 4km strip of land near Mount Kilimanjaro, northern Tanzania. This single, limited source renders tanzanite at least a thousand times more rare than diamonds. Tanzanite is a stone of transmutation, shifting from lilac blue to sapphire blue and into deep blue violet. In faceted form it is stunning, celebrated as the Gemstone of the 20th Century and