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10 Interesting Tanzanite Facts

10 Interesting Tanzanite Facts

Tanzanite is a zezite mineral composed of calcium hydroxide silicate with aluminum, with a blue and purple color. It was first discovered in the Mererani Hills of the Manyara region of northern Tanzania in 1967, near the city of Arusha and Kilimanjaro. Today it is used as a gem, can be distinguished by its marked trichroism, represented by its blue sapphire, violet and burgundy color according to the orientation of the crystal.

This glass can change its aspect depending on the lighting and conditions it is in, its blue color becomes more evident when exposed to fluorescent light, and incandescent lights make it more appreciated with violet tones. The rough tanzanite is usually reddish brown and must be heat-treated at 600°C in the oven to highlight the purplish blue color. Tanzanite is a very rare gem. It is only found on the slopes of Mount Kilimanjaro and was named after Tanzania, the country where it was located, by the company Tiffany & Co. Due to its relatively low hardness, Tanzanite is used for necklaces and slopes.


In this list we will find 10 insteresting Tanzanite facts:

  1. The tanzanite has a variety of blue and zoisite purple colors.
  2. The tanzanite and its violet-blue can easily be compared to beautiful sapphires.
    The tanzanite was found in 1967 in the Mererani hills, located near the city of Arusha, northern Tanzania.
  3. The tanzanite next to the zircon and the beautiful native turquoise stone for December.
  4. When tanzanite is carved once it becomes a popular and valued jewelry gem. It stands out for its trichromatism since, depending on the orientation of the crystal, it appears in shades of sapphire blue, violet or green.
  5. The company Tiffany & Co made the Tanzanite name in the marketing campaign aimed at placing the stone in the market and increasing its value.
  6. Tanzania Tanzanite production delivers some US$ 20 million a year to Tanzania, although the value of the carved jewelry amounts to US$ 500 million a year.
  7. Some of these stones found have a slight yellow-brown pigmentation, which can be removed with thermal treatment at approximately 500 ºC.
  8. Tanzanite has a hardness of 6.5 – 7 on the Mohs scale.
  9. It is a unique deposit of tanzanite in the world. There the mineral is accompanied by metamorphic slate, gneiss, and quartzite.
  10. Its exclusivity is the main reason for the high price of this stone, which is also called “the indigo diamond” for its rarity.

More interesting facts about Tanzanite

The tanzanite is the most important of the three varieties of the zoisite. It is an aluminum calcium silicate belonging to the epidote group.
When the stone is of good quality, it is ultramarine blue to sapphire blue. Under artificial light, the color is an amethyst violet. The trichrome colors, which can be seen with the naked eye, are blue, purple-red and greenish yellow-brown.
The color is purplish brown due to the heating and the vanadium; this makes it obtain that blue that is how it is commercialized. The shine is vitreous. Despite their color, they are very transparent.
Geological origin: It has a metamorphic background in all areas of regional metamorphism.
Deposit: it is a rare gem, found only on the slopes of the Merelani in Tanzania, discovered in 1967.

Interesting facts about Tanzanite: Imitations and synthesis


All these jewels are heat-treated to achieve their characteristic blue color.
Tanzanite can be easily confused with iolite, which is also trichrome, amethyst, sapphire, and spinel.
But it can be distinguished from all of them by its physical and optical properties.

Curiosities of the Tanzanite

Legend has it that the Masai discovered the tanzanite after a fire caused by lightning or lightning and that a few yellow-brown stones not very attractive (Zoisite) became a beautiful blue-purple-purple color.

The tanzanite is a magical jewel of trichrome, like the iolite next to the andalusite, whose characterization is fundamental is that all and I say all those that are marketed have undergone a series of hot work that gives them that color so characteristic of the jewel.
Unlike other gems, it is insensitive to acids. However, we should not clean them with ultrasound but with water, soap and a soft cloth.

As for the name tanzanite, only found in the hills of Merelani, Tanzania was introduced by the Tiffany’s New York jewelry company , originally had the name “blue zoisite” but its name in English did not sound very good, as it looked like “blue suicide”, so Tiffany´s decided to put a more commercial name to be able to introduce it in the market, and chose the name of the country called Tanzanite. Between 1967 and 1972, approximately 2 million carats of Tanzanian jewelry were extracted from the mines before the government nationalized them.

The world’s largest tanzanite is weighing 737.81 carats. There is a very famous and beautiful specimen of about 242 carats called the “Queen of Kilimanjaro,” Tanzania set in a tiara with 803 tsavorite and 913 brilliant garnets, this impressive piece is part of the private collection of Michael Scott, Apple’s top executive.

In June 2003, the Tanzanian government banned the export of raw tanzanite to India (where the vast majority of gems are carved in Jaipur) to encourage local industry, in an attempt to stimulate the economy and recover profits. In April 2005 the company under the name Tanzanite One Ltd, openly announced that it was taking control of the production of Block C (the main deposit, divided into five blocks), with this the price of gross has been increasing, as well as the company has been settling in the market.  In August 2005, the world’s largest tanzanite to date at 16,839 carats, or 3.4 kg, was found in Block C.