Tanzanite Jewelery
What a spectacular colour!
Spectacular and magnificent is the deep blue of Tanzanite, ranging from ultramarine to a light purplish blue. The most coveted colour is a blue which shows a purplish hue shimmering around it, which is extremely spectacular in sizes above ten carats. Typical for Tanzanite is the appearance of several colours in one and the same stone: depending on the perspective, the stone appears blue, purple, or dun yellow. Most rough crystals, however, show a disturbingly large proportion of brownish-yellow, but the cutter may cure this by carefully heating the stone in an oven to about 500°C. In the course of this heating , utmost concentration is demanded, for it is essential to determine the moment when the colour turns blue. Heating is therefore a treatment which is generally accepted in the trade, however, the rough stone has to be as free of inclusions as possible, as otherwise the process will lead to fissures in the stone.
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