Alexandrite

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 Tokovaya 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.

Beautiful alexandrite in top quality, however, is very rare indeed and hardly ever used in
modern jewellery. In antique Russian jewellery you may come across it with a little luck, since
Russian master jewellers loved this stone. Tiffany’s master gemmologist George Frederick Kunz
(1856-1932) was also fascinated by alexandrite, and the jeweller’s firm produced some beautiful
series of rings and platinum ensembles at the end of the 19th and beginning of the 20th century.
Smaller alexandrites were occasionally also used in Victorian jewellery from England.

The magic of changing colours

The most sensational feature about this stone, however, is its surprising ability to change its
colour. Green or bluish-green in daylight, alexandrite turns a soft shade of red, purplish-red or
raspberry red in incandescent light. This unique optical characteristic makes it one of the most
valuable gemstones of all, especially in fine qualities.

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.

Like many other gemstones, alexandrite emerged millions of years ago in a metamorphic
environment. But unlike many others, its formation required specific geological conditions. The
chemical elements beryllium (a major constituent in chrysoberyl) and chromium (the colouring
agent in alexandrite) have contrasting chemical characteristics and do not as a rule occur
together, usually being found in contrasting rock types. Not only has Nature brought these
contrasting rock types into contact with each other, but a lack of the chemical element silica (the
second most common element in the Earth's crust) is also required to prevent the growth of
emerald. This geological scenario has occurred only rarely in the Earth's history and, as a result,
alexandrite crystals are very scarce indeed.

Nowadays not only from Russia

Russia has remained the primary source of alexandrite since gems from the mines of the Urals
became available on the market. When the Russian deposits were thought to have been
exhausted, interest in the unique colour miracle decreased - especially since alexandrites from
other mines hardly ever displayed the coveted colour change - . But the situation changed
dramatically in 1987, when alexandrites were discovered in a place called Hematita in Minas
Gerais, Brazil. The Brazilian alexandrites showed both a distinctive colour change and good
clarity and colour. Thus the somewhat dulled image of the miraculous stone received another
boost. The colour of the Brazilian stones is admittedly not as strong a green as that of Russian
alexandrite, but the colour change is clearly discernible. Today Hematita is one of the most
important deposits of alexandrite in economic terms. Occasionally alexandrite with chatoyancy is
discovered there, an effect which has not yet been observed in Russian alexandrite.
Alexandrites are also recovered from sources in Sri Lanka, but the hue of these stones
compares less than favourably with that of the Uralian alexandrites. They appear green in
daylight and a brownish red in artificial light. The Tunduru area in southern Tanzania has also
produced some outstanding specimens since the mid-1990’s. Alexandrites are also found in
India, Burma, Madagascar and Zimbabwe. Although this stone is still considered a rarity,
specialised gemstone dealers do stock it, especially since improved trade relationships
between Russia and the rest of the world have ensured a better supply of Russian alexandrites
to the market.

A gemstone for experts and gemstone lovers

With its good hardness of 81/2, alexandrite is an uncomplicated stone to wear. The more distinct
the change of colour, the more valuable the stone. A fine alexandrite should show a vivid bluish-
green in daylight and a purplish-red in artificial light, without any trace of undesirable brown or
grey. If the origin of the stone is known beyond dispute to be Russia, we are talking about a real
rarity of enormous value. Finely faceted alexandrites above one carat are thus among the most
expensive gemstones in the world, rarer than fine ruby, sapphire or emerald.
Alexandrite is a stone for experts, enthusiasts and connoisseurs, a true understatement stone.
Its uniqueness and high value are not evident at first sight. The mysterious colour change will
only occur on exposure to different light sources. But if you really get involved in alexandrite,
you will be utterly fascinated by this gem. Maybe you will also feel some of the mysterious magic
and lore ascribed to it. It is considered a stone of very good omen. In critical situations it is
supposed to strengthen the wearer’s intuition, and thus help him or her find new ways forward
in situations where logic will not provide an answer. Alexandrite is also reputed to aid creativity
and inspire imagination.

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***Information about gems on this page provided by international colored gemstone association website.
For more information please visit www.gemstone.org.
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