Tanzanite’s only source is a 4km strip of land near Mount Kilimanjaro making it a thousand times more rare than diamonds. Tanzanite is trichroic, meaning that in its rough form, it radiates three different colors from each of its crystallographic axes: blue, violet and red. Once cut and polished, tanzanite ranges from electric violets to vibrant blues, deep royals and rich indigo’s. Let’s learn more about this unique and stunning gem!
Where Does Tanzanite Come From and How is it Formed?
Tectonic plate activity and intense heat formed Mount Kilimanjaro and the Mozambique Orogenic Belt which is one of the most mineral-rich places on Earth. When tectonic plates collide, the rocks reach a near melting-point and produce beautiful crystal structures. Gems are formed by the coming together of two plates that can contain a variety of different minerals, and because of this combinations that are specific to one area may occur.
This explains why tanzanite is only found in one area in the world. The morphing together of two tectonic plates in this specific area of Tanzania resulted in a particular mix that has not been discovered anywhere else in the world. The conditions that created the tanzanite deposit at the foothills of Mount Kilimanjaro are thought to be so unique, that geologists believe the chances of another batch of tanzanite being created are only about one in one million.
Tanzanite is the purple, violet and blue variety of zoisite and was first brought to market by Tiffany & Co. in the 1960’s. The future of tanzanite is unclear since the world’s production only comes from a small area in Tanzania and its supply is likely to run out by the end of the current generation. Tanzanite became so popular by 2002 that it was added to the list of alternative December birthstones.
What Color is Tanzanite?
Tanzanite is a pleochroic gem, meaning it displays multidimensional color. When viewed from different directions three different colors can be seen; Tanzanite is the only gemstone that is trichroic in nature. This makes cutting a crucial element in determining the color the consumer sees when the stone is cut and set in jewelry. The most coveted color is a vivid blue surrounded by a delicate hint of purple, which has an indescribable effect in all sizes.
Typically tanzanite color grading is spread into a range of hues from violet blue to blue violet and based on tone and saturation of color. While the deeper colors have greater value, tanzanite with moderate to light colors is still desirable and sometimes preferred by consumers. Tanzanite appears more blue during the daylight, whereas at night in incandescent light you can see the red flashes throughout the stone.
The color of Tanzanite is strongly related to the presence of vanadium and titanium in its crystallographic structure. Untreated tanzanite is typically brownish so most blue tanzanites owe their color to heat treatment which reveals the gem’s attractive pleochroic blues and violets. On the Mohs Scale, Tanzanite has a hardness of 6.5-7 which means while it can be worn daily, it should be treated and stored carefully.
Tanzanite’s mesmerizing color is unique in the world of gemstones and if the idea of owning something few others possess is appealing then this is the stone for you! Give us a call at 303-385-8449 or click here to schedule an appointment.