Alexandrite

History
Alexandrite is named in honour of Tsar Alexander II, as it was supposedly discovered on his 16th birthday: April 17, 1834, the occasion of his coming of age. A Finnish mineralogist made the discovery on the slopes of the Ural Mountains, north-east of Yekaterinburg/Ekaterinburg. Alexandrite was originally viewed as Russia’s national stone, since it united the tsarist colours of red and green.

 

Colour
In daylight, alexandrite tends to appear in a mossy green, sometimes with hints of blue, magically transforming into colours ranging from raspberry red to amethyst purple under the warm light of incandescent illumination.

 

Gemmological Properties
This intriguing gem changes colour like a chameleon; this so-called “night-and-day stone” is the third fascinating member of the chrysoberyl family. Again, how is this colour-changing phenomenon to be explained? The trace element responsible for alexandrite’s colour is chromium. Chromium itself does not change in different light conditions, but it is the composition of the light that does. Daylight contains more blue radiation, whereas light from an incandescent source is richer in red. The prevailing colour is reflected within the alexandrite; in other words, its colour appears to change according to the light conditions.

 

Mining Areas
For almost a century the Urals produced the most beautiful alexandrites, intense in their colour change and large in size. These deposits are now mostly deserted since the emergence of newer sources producing fine stones, such as the famous deposit of Hematita in Brazil and some sources in Southern Africa, Sri Lanka and India.