Found in just one place on earth, tanzanite is a relatively recent discovery. Tiffany & Co named this blue-violet variety of zoisite in honour of Tanzania, where it was first unearthed in 1967. Because the crystals show different colours depending on the viewing direction, cutters can fashion gems with a range of colour from violetish blue to bluish violet depending on how much weight they want to retain from the rough.
Birthstones & Anniversaries
Tanzanite is a birthstone for December, along with zircon, turquoise and blue topaz. Tanzanite is also the gem for a 24th anniversary.
Tanzanite has only one source: the hills of Merelani in northern Tanzania.
Masai tribesman Ali Juuyawatu is credited with finding the first tanzanite crystal.
Tilt tanzanite and you’ll see three distinct colours in three crystal directions.
There are a number of processes used to alter the colour or apparent clarity, or to improve the durability of gems.Learn More
Some gemstones have synthetic counterparts that have essentially the same chemical, physical and optical properties, but are grown by man in a laboratory.Learn More
Any gem can be imitated – sometimes by man-made materials or by natural materials chosen by man to impersonate a particular gem.Learn More
Why We Love This Gemstone
Tanzanite is pleochroic, showing three different colours when viewed from different directions.
One Place on Earth
Commercially mined in only one place, tanzanite is rarer than diamond.
Tanzanite's rich blue-to-violet hues can be exceptionally beautiful.
Assessment of the following characteristics determines tanzanite’s value.
Deeply saturated violet blue or blue violet are the most valuable tanzanite colours. Paler hues are more commonly found.
Eye-visible inclusions decrease the value of tanzanite, particularly in lighter coloured stones.
Tanzanite is available in a wide range of shapes but cushion and oval cuts are most common.
Tanzanite colour is less saturated in smaller sizes. Gems must be above five carats in size to have fine colour.
Tanzanite Quality Factors: The Comprehensive Guide
Explore sources, gemmological research and the role of gems in history.
Natural-Colour Tanzanite and Yellow Sapphire – Tucson 2014Duncan Pay , Apr 30, 2014 Read more in English
Merelaniite Inclusions in TanzaniteAugusto Castillo, Tyler Smith, and John A. Jaszczak , Aug 9, 2018 Read more in English
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