Tanzanite is a gem form of zoisite, found only in the Arusha region of Tanzania. Mining is very deep, as gemstones easily go for $250 - $1000+ per carat. Crystals are also produced, of varying quality given largely that anything with a gemmy area within it gets cut. Also most are dinged, so getting pristine specimens is very difficult. Most pieces are heat treated, which mimics the natural geology that gives the crystals that amazing blue-purple color. Natural crystals are often a yellow-brown, although some like this one have a natural blue-purple color. This piece is particularly good in that it shows off good color with reasonable clarity, but also shows the typical natural color on the base. It also hasno damage. There is a very slight "line," on the left shoulder where there is some white clay as a natural inclusion that in some pics creates the illusion of a ding near the termination. Comes mounted on an acryllic base. It weighs 12 carats.