QUALITY ROUGH

ALEXANDRITE ROUGH

This is a specimen I picked up on my last trip to Tanzania. One mine is producing some material but the  clean cut stones are  VERY RARE  at app 1000 $ carat.This is a fairly new field. This a specimen from the mine-the colour change is not that strong but they are great specimens. We have taken the photo of the specimens under a white light and a yellow light.

Weight 15.11 cts app

Size 16 x 13 x 9 mm app

For cabbing material we have listed some rough aslo at our sister store SEDAGEMS

This rare gemstone is named after the Russian tsar Alexander II (1818-1881), the very first crystals having been discovered in April 1834 in the emerald mines near the River in the Urals. The discovery was made on the day the future tsar came of age. Although alexandrite is a relatively young gemstone, it certainly has a noble history. Since it shows both red and green, the principal colours of old Imperial Russia, it inevitably became the national stone of tsarist Russia.

Alexandrite is very scarce: this is due to its chemical composition. It is basically a chrysoberyl, a mineral consisting of colourless or yellow transparent chrysoberyl, chrysoberyl cat’s eye and colour-changing alexandrite (also in cat’s eye varieties). It differs from other chrysoberyls in that it not only contains iron and titanium, but also chromium as a major impurity. And it is this very element which accounts for the spectacular colour change. Rarely, vanadium may also play a part. According to CIBJO nomenclature, only chrysoberyls displaying a distinct change of colour may be termed alexandrite.