Tanzanite colors
Buying Tanzanite
Where is Tanzanite found?
Common Tanzanite treatments
World-famous Tanzanite
Tanzanite gemology
Tanzanite legends & lore

Tanzanite colors
In good quality the color is ultramarine to sapphire blue. The most popular color is a blue, which shows a purplish hue shimmering around it. Typical for Tanzanite is the appearance of several colors in one and the same stone (pleochroism), which means, depending on the perspective, the stone appears blue, purple, brown or yellow.

Buying Tanzanite
Due to its minor hardness (6.5-7 on Mohs scale) tanzanite is not very resistant. Therefore it should be worn with care, never be cleaned by ultrasonic method and never come into contact with acids.
As the stone is found on one special location only on Planet Earth, it is especially valuable.

Color
The most popular color is a blue, which shows a purplish hue shimmering around it.

Lighting
Typical for Tanzanite is the appearance of several colors in one and the same stone (pleochroism), which means, depending on the perspective, the stone appears blue, purple, brown or yellow. In artificial light tanzanite color appears more amethyst blue.

Clarity
Tanzanite is a transparent gem, yellowish and brown tints are quite common but vanish when heated. Tanzanite cat's eyes are rare and used in facet cut.

Cut
Tanzanite needs experienced cutters to treat it carefully, as the cleavage of the gemstone is very high in one direction, oriented with the direction of the strongest pleochroism. The exclusive stone is cut in any imaginable shapes and forms, from classical round cuts to imaginative designer cuts.

Tanzanite location and deposits
The only known deposit of tanzanite is a five square mile hilltop at Merelani Hills near Ausha, ten miles south of the Kilimanjaro International Airport in Tanzania. Massai-herdsmen passing by noticed crystals sparkling in the sun and opened thus a new chapter in the rich gemstone history.
The tanzanite trade is praised for its management and distribution via reliable and trustworthy official channels to well-reputed gemstone-cutters, and then passed on to the most important jewelers all over the world.

Common Tanzanite treatments
Most rough crystals show a disturbingly large proportion of brownish-yellow tints, which vanish when heated to 752-932 degrees F (400-500 degrees C).

World-famous Tanzanite
Tanzanite gained worldwide fame as a fine and rare gemstone in itself. Tanzanites in especially good qualities and larger sizes are in serious demand and command high prices. It isn't only the spectacular color. Since the stone is found in only one special location in the entire world, it is especially valuable. The desire to own something unique and rare has always been a decisive criterion for assessing the value of special gemstones.

Tanzanite gemology
Species: Zoisite
Color: Sapphire blue, amethyst, violet
Chemical composition: Ca2Al3(Sio4)3(OH) calcium aluminum silicate
Crystal system: Orthorhombic, multifaceted prisms, mostly striated
Hardness: 6.5-7 (Mohs scale)
Specific gravity: 3.35
Refractive index: 1.691 - 1.700
Birefringence: +0.009
Color of streak: White,
Absorption spectrum: 595, 528, 455
Fluorescence: None

The Tanzanite zodiac, myth & legend
Too "young" to have written a page for itself in the books of myth, history, wisdom, the zodiac scheme or the relation between planets and mankind, tanzanite left its mark in present time. It has become so popular that in October of 2002 the American Gem Trade Association (AGTA) announced that tanzanite had joined zircon and turquoise in the traditional list of birthstones for the month of December.