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Emerald Gemstone Varieties @ Jewel Info 4 U
By: Madhubanti Rudra
Different Types of Emerald
Gemstone
Summary: Green is life. Green is
happiness. So is emerald. For ages
it has been a regal choice. But the
common men are often confused at the
time of buying this magnificent
gemstone. Knowledge about the
emerald classification will help you
to sail through the bargaining
process for the right stone. So read
on the article to learn about
different types of emeralds
"He who possesses it shall enjoy
special protection of God"-reads a
talismanic Mughal emerald. This
birthstone of the month of May has
been the passion of Cleopatra and
love of the Mughals. Along with
ruby, diamond, and sapphire, emerald
is an important member of the big
"awesome foursome" and has long been
attributed healing and mystic
prowess. Being associated with the
planet Mercury, emerald is
traditionally believed to cure
diseases like forgetfulness,
epilepsy, stammering and even
insanity. Attributing mystic
qualities to this gem, it is said
that this piece of stone brings
foresight and wisdom to the
possessor.
Emerald (Be3Al2Si6O18) is the
grass-green type of Beryl. Mostly it
occurs in mica schists of
metamorphic-hydrothermal origin. The
formation of emerald involves a
natural process known as
exometamorphism. During this
phenomenon if the basic rock
contains the elements chromium or
vanadium small quantity of it might
get incorporated in the structure of
beryl. This gives the rock its
gemlike green color. Varying amount
of iron also alters the color of the
rock. It has a hardness of 7.5-8 and
a refractive index of 1.57-1.59.
However it is not a gem recommended
for 'everyday' use since it falls in
the category of soft stone. The real
worth of the gem rests in its green
dazzle and variations in shades.
They range in color from slightly
yellowish green to darker bluish
green. The cut of the stone is also
significant. Although faceted
emerald can have round, pear, oval
shapes the emerald cut, that is,
octagonal shape is most preferred.
Inclusions are almost an accepted
fact in emeralds.
Emeralds differ in shine and color
depending upon the locale of its
mine. It is only the Columbian
emerald that has the characteristic
vivid, slightly bluish green tones
of medium-to-medium dark color.
Deposits of the stone are also found
in other parts of the world such as
in Zambia, Zimbabwe, Madagascar and
Nigeria. However Columbia and Brazil
are the leading producers of emerald
today. The mines of Egypt, which
supplied emeralds to Cleopatra, are
not much into production today.
Among the foremost consumers of
emerald are USA and Japan who buy
75% of the world's cut emerald.
COLUMBIAN EMERALD GEMSTONE
 Columbia is the
foremost producer of emeralds. Both
in terms of quantity and in terms of
quality Columbian emeralds lead the
world. The transparency,
crystallization and fire identify a
Columbian emerald. It is the deep
green shade of Columbian emerald
that is taken as standard.
History depicts that when the
Spaniards conquered America the
Egyptian mines were no longer
producing emeralds. The conquest
brought the Spaniards into a land
laden with one of the world's most
precious stones. It is primarily the
rich colour and proverbial quality
of emerald from the Andes mountain
ranges that has distinguishes
Columbian emerald from African or
Brazilian emerald. It is described
as 'green on top of green'. In the
Columbian mines emeralds are worked
by hand and plucked from
carbonaceous shale. Muzo and Chivor
are two of Columbia's most important
mines. Emeralds mined in Muzo are
slightly yellowish whereas those
from Chivor are bluer. It is also
believed that there is a symbiotic
relationship between Columbian
emerald and the gold of the country.
The combination is therefore
splendid. It is left to your
imagination what jewellery might be
produced by the country's craftsmen.
BRAZIL EMERALD GEMSTONEBrazil has been supplying
emerald to the world market since
the 1980s. Typical Brazilian
emeralds are lighter and yellowish
AFRICAN EMERALD GEMSTONE
 African countries
like Zimbabwe, Zambia, Madagascar
and Nigeria have deposits of beryl
and are the second most leading
producer of emerald. Unlike
Columbian emerald, African emerald
lacks the intensity of green colour. Due to the presence of a
higher percentage of iron in these
emeralds the green colour gets blunt
and a grayish tinge takes over.
Therefore it is described as 'green
on top of grey or brownish grey'.
Emerald from Zambia often has the
defect of being 'overblue' that is
when viewed under incandescent bulb
it appears to be bluish. It might be
mentioned here that when emerald was
first discovered in Zambia it was
not considered emerald at all. This
was because although it was bright
it had a lighter to medium hue. The
confusion was deepened by the fact
that it had much less inclusions and
could be doubted as synthetic. Later
on this doubt was cleared and
Zambian emerald made emerald
affordable to a lot of people..
Emeralds from Zimbabwe are smaller
is size and lighter in shade.
However the term 'African emerald'
is a misnomer. It simply denotes
green fluorite.
Some of the other countries, which
produce emerald, are Russia, India
and Australia.
RED EMERALD OR BIXBITEThis gem
which is basically formed out of the
mineral berl takes its colour due to
the presence of manganese. It is
found only in a few deposits of
Utah's Wah Wah mountain. This makes
it one of the rarest gems of the
world all the more so if it is
facetable.
SYNTHETIC EMERALD GEMSTONEThe synthesis of
emerald began in the 1930s when it
was done by a process known as
Farben and the Chatham processes.
However the process did not run out
to be commercially much viable.
Later on in the 1960s another
process known as hydrothermal flux
process began to be used in the
production of synthetic emerald. In
this method crystal nutrients are
dissolved in an acidic solution of
water and chemicals at a very high
temperature and pressure. It is then
allowed to crystallize in a cooler
chamber of the reactor. This method
of emerald production proved to be
much viable and by 1980 as much as
500,000carats of gem had been
manufactured through this process.
Manufacturers Biron, Chatham,
Kyocera, Gilson, Inamori, Farben,
Lechleitner, Linde and others
produce synthetic emeralds today..
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