Tanzanite, the exquisite blue-purple variety of the mineral zoisite, is only found in one part of the world. Named for its limited geographic origin in Tanzania, tanzanite has quickly risen in popularity since its relatively recent discovery in 1967. Due to pleochroism, tanzanite can display different colors when viewed from different angles. Therefore, stones must be cut properly to highlight the more attractive blue and violet hues, and de-emphasize the undesirable brown tones. The majority of tanzanite on the market today is heat treated to minimize the brown undertone found naturally and to enhance blue shades that can rival fine sapphire.
This gorgeous gem has become so popular that in October of 2002 the American Gem Trade Association (AGTA) announced that tanzanite had joined turquoise and blue zircon in the traditional list of birthstones for the month of December, thus making tanzanite the newest December birthstone!