Tanzanite is the newest birthstone for the month of December. Most tanzanite sold in jewelry today has a blue to bluish purple to bluish violet color that is produced by heat treatment. Its color has an interesting feature – it changes depending upon the angle of viewing. If you have tanzanite jewelry, look at the stone face up and then from the side – you might be able to notice a slight color difference.

Tanzanite was added as a modern birthstone in 2002. “Tanzanite” is a trade name that was first used by Tiffany and Company for gem-quality specimens of the mineral zoisite with a blue color. The gem was first discovered in the 1960s in the country of Tanzania, and that is the origin of the gem’s name. Shown here is a violet-blue tanzanite measuring 7 x 5 x 3 millimeters in size and weighing 1.02 carats, antique facet cut. This grade of tanzanite is often seen in mall and chain store jewelry.