Secrets from the Vault
Tanzanite is an extraordinary gemstone that has rapidly become one of the most coveted gemstones in the world. It is named after the African state of Tanzania, the only place in the world where it has been found.
Upon its discovery in 1967, Tanzanite was enthusiastically celebrated by the specialists as the gemstone of the 20th century. They held their breath in excitement as they caught sight of the first deep- blue crystals which had been found in the hills north of Tanzania.
Millions of years ago these precious crystals grew in deposits on the inside of these unusual elevations. For a long time, they were hidden from the eye of man until one day some passing Masai shepherds noticed some sparkling crystals lying in the sun and took them along with them.
Today the search is carried on for the crystals. As a rule, only small grains are found, but now and then the mineworkers succeed in finding a larger crystal.
The deep blue of the tanzanite is fantastic and runs from ultramarine blue to light violet-blue. The most coveted color is a blue surrounded by a delicate hint of purple, which has a particularly wonderful effect in sizes of larger than 10 carats.
The well developed polychromatism of the tanzanite is typical, depending on the angle from which you look at it; the stone may appear blue, purple or brownish-yellow. Most raw crystals are somewhat spoiled by a brownish-yellow component, though it can be made to disappear by the cutter if the stone is carefully heated in an oven to approximately 500 degrees. During the procedure, careful attention must be paid to the moment at which the color turns blue.
This burning is a method of treatment which is regarded as customary in the trade, but the raw stones must be as free of inclusions as possible, otherwise fissures may occur. Working with tanzanite can sometimes give even the most experienced cutter a bit of a headache, the cleavage of this gemstone is very pronounced in one direction.
This exclusive gemstone is cut in every imaginable shape from the classical round shape to a number of imaginative designer cuts.