Tanzanite

Tanzanite is the gemological name for a variety of the mineral zoisite , aluminum silicate and calcium .

Tanzanite
Tanzanite after cutting
Formula	Ca 2 Al 3 (SiO 4 ) (Si 2 O 7 ) O (OH)
Physical properties
Colour	Sapphire Blue to Amethyst Purple
Trait color	White
Shine	Glass
Transparency	Transparent
Hardness	6.5 - 7
Cleavage	Perfect
Kink	Uneven. Fragile
Density	3.35 g / cm³
Syngonia	Rhombic
Refractive index	1,691 - 1,700

Tanzanite was discovered in March 1966 on the Merelani plateau, near the slopes of Kilimanjaro . The stones originally found were taken as sapphires, but already in 1967 they were identified as the new mineral tanzanite.

The mineral is mined only in Arusha province in northern Tanzania .

Tanzanite Processing

He became famous thanks to the American jewelry company " Tiffany " ("Tiffany"), which proposed the name in honor of Tanzania, where there is the only deposit in the world. Competent advertising policies, rarity, gorgeous color and the use of jewelry made from it by movie star Elizabeth Taylor contributed to the popularity.

There are blue, purple and yellow-brown colors, the latter after heat treatment also become blue-violet and used in jewelry.

In stones of good quality, the color is ultramarine - or sapphire- blue. Under electric light, it acquires an amethyst- violet hue. When heated to 400-500 ° C, brownish and yellowish shades disappear and the blue of the stone deepens. Tanzanite cat's eye is also known.

The deposit is represented by veins and cracks with overgrown crystals in gneisses .

Glass imitations of tanzanite and doublets made of glass with a tanzanite top or two colorless synthetic spinels fastened with blue glue appear on the jewelry market. Tanzanite can be confused with natural and synthetic sapphire . The recently discovered green variety of zoisite is called chrome (green) tanzanite.

Used in the manufacture of jewelry .

Large tanzanite and sapphires surrounded by waltz diamonds. Jewelry house "Moiseikin"	Brushed Tanzanite	Ring (Exquisite Tanzanite). Mark Schneider	Deep blue tanzanite