Alexandrite - One of the world's rarest changing color gemstone!

The story of Alexandrite starts with the Finnish mineralogist Nils Gustaf Nordenskiöld who was working for the Czar Nicholas in the Ural Mountains of Russia, near the city Yekaterinburg in the Tokavaya mines in 1834. During those times in the area they were mining a lot of gemstones including amethyst, topaz and large quantities of emeralds. The major problem it was that the emeralds were not the same quality as the ones from Columbia. On 23rd April 1834 Nils discover what he thought it was an emerald of great quality, even greater of the ones from Columbia so he introduce the stone in the same day to the Czar. Well during the evening by the light of the camp fire the newly discovered gemstone which has been green by daylight shows a fabulous shade of red.
The irony is that most of the gemstones during the time have been accepted at the beginning because of superstitious reasons and the same it happen in Alexandrite case. Seeing the color change of the gemstone the Czar thought this is a message from God because the Russian army uniforms at that time where the same colors green and red. He thought that the new discover stone will help them in winning wars. Based on this superstitious the gemstone cause sensation in the Russian society and have been named after Alexander II in 1842.

Well you might ask yourself how Alexandrite is changing color. The gemstone results from small scale replacement of aluminium by chromium ions in the crystal structure. This causes intense absorption of light over a narrow range of wavelengths in the yellow region of the visible light spectrum. I will explain it to you a little bit more simple: daylight contains high proportions of blue to green light, although the human eye adjusts to see it as a white light and so the stones appears green. Incandescent lighting has a higher proportion of red and this is reflected in the change of color when view in this light.
One of the main reasons why Alexandrite is so rare its because of his chemical nature and the rarity of the conditions for its growth. The conditions for growth require the absence of silica which is one of the most abundant elements on the planet. So how rare Alexandrite is? The gemologists around the world are saying that it is at least ten thousand times rarer then a diamond and only one in a million persons actually owns a piece of jewelry with Alexandrite.
Alexandrite is the birthstone for the month of June.

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