Alexandrite
"Look, here it is, the prophetic Russian
stone! O crafty Siberian. It was always green as
hope and only toward evening was it suffused
with blood".
Nikolai Leskov, The Alexandrite, Mysterious
Interpretation of a True Fact (1884)
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Tsar Alexander
II (1818-1881) |
The
'gem of the tsars', or simply, the 'tsar stone',
Alexandrite is a gemstone forever linked to the
ruler for whom it was named, Tsar Alexander II
of Russia (1818-1881), the country he ruled and
the twilight of Russian aristocracy.
Alexandrite is the ultimate gemstone of duality
and for me, its twin colours symbolically embody
the Russian character, shifting fortunes of hope
and hardship. Writing just three years after the
death of Tsar Alexander II, Nikolai Leskov
cleverly tied together the fates of Russia, the
Tsar and the gem that received his name,
defining Alexandrite as a prophetic stone. One
of the classic Russian writers of the 19th
century, Nikolai is regarded by many Russians
as, "the most Russian of all Russian writers".
Coming to the throne, liberal-educated Alexander
knew the path to take to help his people, but at
the same time, I guess it's good to be king.
Assuming power at the tail end of a humiliating
defeat in the Crimean War, Alex thought the time
right to modernise. Hailed as 'Tsar Liberator',
the hopeful nature of his industrial reforms,
new judicial administrations and most
importantly, ending serfdom, correspond to
Alexandrite's daylight greens or as Nikolai put
it, "green as hope".
But by the end of Alexander's rule, these very
reforms had created a hotpot of revolutionary
zeal, which true to his autocratic legacy, was
ruthlessly suppressed. Native languages were
banned and over 250,000 people were exiled to
Siberia, an irony considering Alexandrite was
discovered in the Ural Mountains. These woes
came to a head in 1881, when it was third time
lucky for the People's Will, a radical
revolutionary group that succeeded in
assassinating the Tsar. In the end, Alexander's
rule, in semblance to Alexandrite's night time
reds, was quite literally, "suffused with
blood". Even though the writing was on the
wall, Alexandrite became a potent symbol of hope
and nationalism for Russian tsarists after
Alexander's death, not only because of its name
and alleged discovery on his birthday, but also
because this extraordinary gem can echo the
Imperial Russian Military colours of red and
green. Three tsars later, the Bolsheviks took
power and it was finally curtains for the
Russian monarchy.
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Alexandrite & Diamond 18K Yellow
Gold Ring |
If you haven't already guessed from the above or
this section's lead photograph, colour change
defines Alexandrite. A member of the Chrysoberyl
family, Alexandrite is its most coveted variety.
Chrysoberyl was named by German geologist
Abraham Gottlob Werner in 1790, using the Greek
'chryso' (golden) and 'beryl' (green gemstone).
Chrysoberyl is a particularly brilliant gemstone
especially noted for its cat's eye variety (click
here) and although rare, it also changes
colour, resulting in Cat's Eye Alexandrite (a
favourite with aficionados because it packs a
phenomenal double whammy). Most Chrysoberyl is
coloured yellow due to iron trace elements, but
vanadium very rarely yields vivid green examples
(click here), while
Alexandrite is coloured by chromium. Chromium is
the Midas element that gives Emeralds and some
Rubies their signature hues.
So it's clear. If Chrysoberyl doesn't change
colour, it isn't Alexandrite. Sure, there are
other colour change gems, and a few of these are
covered in this section, but most of these
display a colour shift (a colour change where
the two colours are near each other on the
colour wheel) rather than the dramatic colour
jump of Alexandrite. Alexandrite is pleochroic (click
here for more), or getting more technical,
trichroic (three-coloured). This means each
Alexandrite crystal has three colours, green,
red and yellow, whose intensity changes when it
is viewed from different angles, but
confusingly, this has absolutely nothing to do
with its colour change. While you can read more
about how colour change works
click here, its
down to natural (candescent) and artificial
(incandescent) light having different amounts of
the spectral colours (blue, green, orange, red,
violet and yellow light) and the way chromium
absorbs and reflects light. Chromium absorbs the
yellow spectrum as white light passes through
Alexandrite, leaving an even split of blue and
green. Sunlight is pretty balanced,
proportionally containing more of the green our
eyes favour, so it appears green in candescent
light, while incandescent light has more red, so
its colour changes to red. Simplistically, the
better the concentration and configuration of
chromium in Alexandrite, the better the colour
change.
You may be wondering if the famous Alexandrite
description 'Emerald by day' and 'Ruby by night'
is really accurate. In his book, Precious Stones
and Gems (1898), Edwin Streeter says, "It has
been said that the Alexandrite is an Emerald by
day and an Amethyst at night", and this is
telling. In reality, Alexandrite is not
dependent on the colours of the change. In
candescent light, Alexandrite can appear
blue-green, forest green, green, khaki, teal or
yellowish-green, and combinations thereof, and
brownish-red, orangey-red, red or
reddish-purple, and combinations thereof, in
incandescent light.
The single biggest value consideration of
Alexandrite is its colour change. Any colour
change gem is judged by the strength of its
change, and how attractive and distinct its
colour is in both candescent and incandescent
light. Colour preference is subjective, so I am
not going to dictate tastes, but the 'ideal'
Alexandrite will display distinct medium toned
intense colours in both light sources, with the
pure daylight greens to night time reds valued
highest. Alexandrite that displays a percentage
colour change of less than 30 percent or visible
greyish, yellowish or brownish tints will be
priced accordingly. Nevertheless, Alexandrite
with a pure change of 90 percent or more is an
impossible rarity for a gem that many regard as
the rarest of them all. Good-looking colours
that dramatically change is the pinnacle for
Alexandrite, but actually seeing it change
colour is dependant on several factors,
including the intensity and purity of the two
light sources, your eyesight, pleochroism, time
of day, and even the weather. Standing under
kitchen fluorescents with a cigarette lighter is
probably not the best viewing environment;
please just use your common sense. This alludes
to a potentially confusing aspect of assessing
colour change, called 'bleed'. This is when a
colour change gem's two colours are visible at
the same time. As most of us live in places
where mixed lighting is the norm, 'bleed' is
common, especially for a light sensitive colour
change gem like Zultanite. Alexandrites that
genuinely show an excessive bleed, diminishing
their colour change, will be priced accordingly.
Alexandrite is classed as a Type II gemstone (click
here for more), meaning you're probably
going to encounter visible inclusions,
particularly when over 1 carat. For most gems, I
preach the old mantra, "that as long as
inclusions don't effect your perception of
beauty, they don't matter", but in the case
of Alexandrite more inclusions often accentuate
the colour change. Whether you select a cleaner
Alexandrite with a lesser change or a more
included Alexandrite with a better change is up
to you, just be aware that colour change is the
key value determinant. Because of its intrinsic
scarcity, Alexandrite is rare and expensive in
any size. Most of what's available is a quarter
to a half a carat, with the two, three and five
carat markers resulting in exceptional price
increases due to their comparative rarity. A
fine quality 10 carats plus Alexandrite is
either off to a museum or the realm of wealthy
private collectors. Again, because of its
inherent scarcity, Alexandrite is typically cut
to maximise yield, which can result in
proportions, windows (click
here), inclusions and other flaws you'd
baulk at if it was in any other gem. As long as
the gem changes colour and doesn't look
frightfully ugly, this is simply the nature of
the beast. In my experience, the most common
shapes are cushions, octagons, ovals and rounds.
Often described as the rarest of gemstones,
Alexandrite's rarity is inarguably its biggest
asset and, along with its colour change, the
main reason for its enduring popularity and high
price. A lot has been written about the original
Russian Alexandrite deposit, with many
conflicting tales about when it was unearthed,
named and by whom. The Emerald deposit (Izumrudnye
Kopi) on the Tokovaya river where Alexandrite
would later be found was discovered by chance in
1830 and by 1833 the as yet unnamed Alexandrite
was found. Although it was undoubtedly Finnish
mineralogist Dr. Nordenskjöld who figured out
what is was, suggesting the less politically
savvy name of Diaphanite, in 1834, Count
Perovskii coined 'Alexandrite', presenting it to
the future Tsar Alexander II on his 16th
birthday. But if Dr. Nordenskjöld lost out this
time, his time would come. Publishing the first
scientific paper on Alexandrite in 1842, he
later discovered and named one of the green
Garnet queens, Demantoid.
Russia and Sri Lanka were the only known sources
of Alexandrite for approximately 90 years,
despite the fact that no significant Russian
Alexandrite was recorded since the 1917 Russian
revolution. With the fall of the Soviet Union,
rumours of new mining circulated (circa 1995).
In 2005, Coloured Stone magazine reported,
"new activity in this area", and in October
2006, Tsar Emerald began renewed production of
the old Malyshev Mine that originally opened in
1833. While I'm not holding my breath, Russia is
a vast land, so who knows what the future will
bring. Even though I don't put credence purely
in pedigree, some will pay a premium for
certified Russian Alexandrite, even if low
quality, which makes absolutely no sense to me.
While Brazil, Burma, Madagascar, Mozambique, Sri
Lanka, Tanzania and Zimbabwe have all produced
small quantities of marketable Alexandrite,
India is currently the most significant
producer. Discovered in Chhattisgarh in 1994 and
in neighboring Andhra Pradesh in 1996, Indian
Alexandrite production is limited, constituting
a tiny amount of the regular Chrysoberyl pulled
from the earth.
Without a doubt, Alexandrite is one of the
rarest, interesting, phenomenal and collectable
of all gemstones. Let's face it, Alexandrite's
got it all; beauty, sporadic availability,
exclusivity (due to its high price), a cool
name, fascinating history, bewitching folklore,
is a birthstone for June, and to top it off, it
even changes colour!
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Colour Change Garnet
While colour change gems have been popular since
Alexandrite's 19th-century discovery, Colour
Change Garnets weren't reported until the
seventies and it took the discovery of
'alexandrite-esque' Colour Change Garnets from
Tanzania's Umba Valley in 1987 and Bekily in
southern Madagascar in the late nineties to
really spark interest. Colour Change Garnet is
an extremely rare variety of Malaia Garnet (a
Pyrope and Spessartite mixture) and its most
striking colour change is due to high amounts of
vanadium, in contrast to chromium which causes
colour change in Alexandrite. Having said this,
chromium along with manganese is responsible for
the colour change in some varieties. While
typically changing from bluish greens to reddish
purples or khaki greens to orangey-reds, other
varieties of Colour Change Garnet include shades
of blue, brown and grey that change to reddish
purplish pinks. Usually only available in small
sizes like Alexandrite, fine Colour Change
Garnets can be visually mistaken for the 'tsar
stone'. While Colour Change Garnet is too
obscure for a clarity type classification,
moderate inclusions may sometimes be visible.
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Colour Change Sapphire
Very attractive, rare and thus highly
collectable, Sapphires are not
regularly available. Typically bluish-purple
(candescent light) changing to purplish-red
(incandescent light), most Colour Change
Sapphires are currently sourced from Tanzania,
although they are also found in other countries.
While their colours vary depending on origin,
Colour Change Sapphires are scarce, especially
over 1 carat and are typically cut to maximise
rough yield. For example, a very large mixed
Sapphire parcel I recently reviewed only yielded
24 Colour Change Sapphires (6x4mm), each
weighing around 60 points (0.60 carats). For
tips on buying Fancy Sapphires (the collective
name for all Sapphires that aren't blue), please
click here.
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Zultanite
First collected and faceted by 'rock hounds'
(mineral enthusiasts) in the late seventies, Zultanite is now mined commercially. A rare
colour change variety of the mineral Diaspore
coloured by manganese, Zultanite hails from a
sole deposit, a remote mountain area in
Anatolia, Turkey. Much like Alexandrite,
Zultanite's name also has a royal connection,
being named by Murat Akgun in honour of the 36
sultans who ruled the Ottoman Empire in Anatolia
in the late 13th century. Noted for its
attractive earthy hues, Zultanite's colour
change is not limited to two basic colours,
exhibiting a range of greens, purplish-reds and
yellows in different light sources. Zultanite
changes from kiwi greens with canary flashes
under sunny skies, to rich champagnes in
traditional indoor lighting and raspberry hues
in candlelight. With up to 98 percent of the
crystal lost during lapidary, Zultanite's very
low yield is one of the reasons it is so rare,
especially in sizes over 5 carats. The clarity
standard for Zultanite is eye-clean (no visible
inclusions when the gem is examined six inches
from the naked eye). Similar to Alexandrite,
Cat's Eye Zultanite is also available. Zultanite
is a personal favourite and I wrote its page on
the ICA (International Coloured Gemstone
Association) website:
www.gemstone.org.
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You probably read the opening
paragraph thinking, "What does Gavin
know about Russia to make such
comments?" Well, my wife is Ukrainian
and her mum Russian, so I've been
fortunate to add a few old wives' tales
to my more conventional understanding of
Alexandrite. Getting thoroughly into
Russian culture and history, I find the
prophetic connection between Alexandrite
and the land of its birth intriguing.
After the fall of Russian imperialism, I
bet many saw a new age on the horizon as
green as the hope mirrored in
Alexandrite at the start of Alexander's
rule. But the horror of WW2, of which
Russia bore the brunt, soon saw Alexandrite's reds again linked with the
colour of blood, becoming known as the
'widow's stone'. Intriguingly, the name
didn't dissuade interest in this gem, so
much so that 'fake' Alexandrite was a
mainstay of Soviet jewellery. This is
doubly ironic considering Alexandrite
will forever be the 'imperial' gem, but
I guess this embodies the uniquely
Russian ability to mix hope with
hardship. My favourite Alexandrite
folktale is that if you only wear one
piece of Alexandrite you will be lonely.
Ostensibly due to its two colours
requiring a partner, herein lies the
problem: Alexandrite is uniquely
individual and notoriously difficult to
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