Alexandrite

Sources

The first known deposits of alexandrite have been the ones of the Tokovaya river, near Yekatherinburg, in the Oural mountains, area very rich in minerals in Russia. It has been discovered randomly while researching emeralds that were abundant in the region back then.
It has been mined intensely until 1913 where the war has stopped the production. In the aftermath, sporadic exploitations, mainly based on the research of beryllium, strategic for the Soviet Union, have permitted the extraction of some rare stones.
Hence, during various years, the alexandrite has been almost impossible to find due to the lack of deposits.
The discovering of alexandrite in the 1970’s in the gravels of Sri Lanka brought back actuality to this rare gem.
In 1987, a new deposit of alexandrite has been discovered near the city of Hematita in Brazil. The alexandrite of Hematita possesses a good change of colour but in tints of raspberry red and blue-green.
In 1995, a new source has been found in Tanzania, at the southern border with Mozambique, close to the city of Tunduru.
The south of Madagascar also produces some specimen of good quality.
Beginning of the year 2000, India has produced alexandrite on the coast of Orissa state. Mines there have been destroyed by the Tsunami in 2004. At the North, in the limits of this state, in the region of Deobhog, small deposits are found randomly with monsoons. Other stones have been discovered recently in the Araku valley, state of Andhra Pradesh. These deposits are currently in exploitation and offer beautiful perspectives for the future of this gemstone.

Varieties

The most beautiful alexandrite, the one of which the changes from red to green are the frankest, comes from historical mines of the Oural mountains, in Russia. Today, these mines are unfortunately almost depleted. Alexandrite from this provenance is the paragon of different qualities of alexandrite.
Alexandrite of Sri Lanka of a colour generally paler can also show a change of colour very strong.
The Brazilian alexandrite has a change of colour, from blue-green to crimson.
The new Indian stones can have exceptional colours even if they are often included.
The alexandrite «cat’s eye», mainly found in India in the state of Orissa, shows a cat’s eye as well as the green-red colour change of alexandrite.