A Little Bit About Treating Tanzanite With Heat

A unique stone that is a fairly recent addition to the gemstone family, tanzanite is popular for its eye-catching hues. Most people aren’t aware of how the stone occurs in nature and how it gets the bright blue and violet color. 

Let’s find out a little more about the origins of this beautiful stone and how it ends up in stunning pieces of jewelry. 

The history of the gemstone

The year was 1967, the location, Northern Tanzania. A Maasai tribesman, out to inspect the location after a ravaging bushfire, stumbled upon some bright, blue crystals. He then alerted a prospector, who at first thought that these crystals were sapphires. However, it quickly became evident that these stones were something else entirely. 

Eventually, Tiffany & Co. recognized the gem’s potential in the jewelry market and named it “Tanzanite '', named after the location and only place on the planet this gem is found.

The original color of the stone 

As a variety of the zoisite mineral, tanzanite occurs naturally as a brownish-red gemstone. The earthy tone of the gem is due to the dominance of the reddish-brown axis. Since tanzanite is trichroic, it appears blue, violet or red when it’s viewed from different angles. However, in its natural state, the blue and violet are not very visible. 

If the stone hadn’t been discovered after a fire had altered its natural state, thereby enhancing the blue, it might never have been discovered when it did. 

A little about heat and tanzanite 

The stone is generally heated between 400-600oC to bring the violetish-blue colors to the forefront. Its original brown color is due to the presence of trace amounts of vanadium in the stone’s crystalline structure. The heat treatment takes about ten hours and needs to be controlled so the gem is not damaged.

The result 

The heating process does not alter the value of the stone; the process simply brings out the colors that the stone is loved for. If the gem was a saturated brown before the treatment, it will turn saturated blue/violet after treated with heat.

At TopTanzanite, customers can find ethically sourced tanzanite gemstones as we are a United Nations Sustainable Development Goals compliant company. As a mine-to-market company, helping clients trace their stones directly back to their mine of origin is also a service we provide, when required.

Our catalog of tanzanite jewelry includes rings, earrings, bracelets, and necklaces. We also offer loose tanzanite gemstones for sale and a customizing facility, should customers want something a little more bespoke.  

Tanzanite is in limited supply, with the mines set to run out within the next two decades. This makes all tanzanite jewelry owners custodians of the rare gemstone.

Browser through our exclusive collection of tanzanite jewelry and follow us on social media for updates and special offers.