Gemstone Buyer's Guide
Tanzanite Gemstones - Birthstone of December
Introduction to Tanzanite
You may recognize tanzanite jewellery by its striking blue or violet colour. Tanzanite comes from the mineral zoisite which was discovered in the foothills of Mount Kilimanjaro. The gemstone is purely for jewellery as it has quite a soft quality, ideal for delicate jewellery such as earrings and necklaces but less suitable for industrial uses. It is a very expensive and rare gemstone as it is only found in one location worldwide.
Tanzanite History
Tanzanite is a relatively new discovery, and was first mistaken for the mineral peridot, when small deposits were found in the Mererani Hills of Northern Tanzania back in the 1960's. Five years later, after a discovery of larger deposits mining began for the jewellery industry.
The most famous and biggest tanzanite is set in a tiara known as the Queen of Kilimanjaro. The stunning piece of jewellery combines 913 brilliant cut diamonds and 803 brilliant cut tsavorite garnets. It's displayed at the gallery of Gold and Gems at the Royal Ontario museum in Toronto.
Tanzanite Facts
- As well as Turquoise Tanzanite is the birthstone for December.
- Tanzanite is named after the East African state Tanzania where it originates. The name was coined by Tiffany's.
- Being discovered in the 1960's it is celebrated as the gemstone of the 20th century.
- Tanzanite is only sourced in Tanzania at the foothills of Mount Kilimanjaro. Sourced only from one place, tanzanite is considered a geological phenomenon.
Tanzanite Colour
The Tanzanite foundation has introduced its own colour grading system which divides the hues between blue violet and violet blue. The most valuable colour of Tanzanite is violet blue also known as triple A. To bring out its violet blue hue, tanzanite needs to be treated at 600 °C in a gemological oven. Gemstone colour is measured in primary and secondary hues. For tanzanite these are blue and purple. Purple lies between blue and red in the spectrum, once treated with heat the hues range from blue violet or purple to violet blue.
Clarity also plays a large part in the value of tanzanite. The gemstone is more valuable if it is bigger and the clarity is flawless to the naked eye.
Caring
Tanzanite is a delicate gemstone, sudden temperature changes may cause the stone to crack. When storing Tanzanite jewellery be sure to keep it in a loose cloth or pouch in a cool place and away from other jewellery that could easily scratch it. Tanzanite jewellery should only be washed in warm mild soapy water.