This massive tanzanite crystal measures 10 cm tall and weighs in at about a pound (388 grams). It is complete all around and displays very impactfully because it is nearly fist sized. As you can see in the photos, it exhibits the traditional famous dichroism of color for tanzanite, blue and purple at alternating 90 degree turns. Tanzanite crystals are often heated at the source, to see if they go to a more uniform and deep blue color for the gem trade. In this case, the heated blue saturation can approach that shown on this entirely natural crystal because the color is so intense and you might therefore doubt the natural origin. However, the colors on natural tanzanites often show a third component down the C-axis, with color in red to magenta or brown, and this color would disappear after the heat treatment: This piece shows a very strong red coloration when lit strongly from the bottom-up, as you would expect of a natural and untreated crystal. Comes with a custom lucite base.