Tanzanite was first discovered at Merelani Hills, Tanzania, in 1967, making it relatively new. Because this stone is only found in one part of the world, it is much rarer than a diamond. Tanzanite is almost always heat treated, which is how it gets its rich color. It exhibits pleochroic properties that can be seen in its brilliant blue, violet and purple hues. Praveen Imports Inc. works with the tanzanite from the time it is mined to the point where it reaches the customer.