December's Birthstone: Tanzanite
Hailing from only one region in the entire world, Tanzanite is one of the accepted birthstones for December. This blue-purple variety of zoisite was named for Tanzania where it's found. Because the crystal composition allows the stone to appear different colors based on viewing direction, cutters can choose to show the bluish purple, or the more favorable pure blue or violet blue hue.
Tanzanite is a relatively new gemstone on the market. The stone was discovered in 1967 in Merelani, Tanzania. Because they presented in intense blue crystal clusters, the hope was that a new Sapphire deposit was discovered. In 1968 Tiffany & Co. named the stone Tanzanite and launched a big ad campaign to promote the new stone.
Due to pleochroism, Tanzanite can appear different colors when viewed in different crystal directions. Most often, both the violet blue and the purplish hues are visible in polished stones. Tanzanites rate between a 6 and a 7 on the Mohs scale, so with proper care and handling this stone can last a lifetime.