Throughout
the history, mankind has marveled at the beauty of gemstones. The charm of gemstones leaves one spell bound. They have been treasured for ages by maharajas, emperors and kings and have been passed on from one generation to another. If one has to
define a gemstone, it can be said that a gemstone is a naturally occurring
mineral with a distinct chemical composition wherein its atoms are arranged in
a definite crystal structure.
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| GEMSTONES |
*(A
mineral can be defined as an inorganic natural substance)
There
are certain exceptions to this definition like amber, pearl, coral, ivory, jet
and ammolite. These are organic gems which have been bestowed upon us by nature,
or in other words produced by a living organism or derived from a natural
process. Another exception to this statement is a gemstone called – Opal, which
does not have a definite crystal structure.
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| ORGANIC GEMS |
Now,
to have a better understanding of what can be termed as a gemstone one needs to
know that most gemstones are minerals but all the minerals are not eligible to
be called as gemstones. For a mineral to qualify as a gem it must have three
characteristics- beauty, rarity and durability.
Beauty: Beauty can be defined
as the overall appeal of the gemstone. It is determined by various factors like
color, cut, clarity and phenomenon. These factors have a big impact on the
pricing of the stones along with a few more factors.
Color:
this factor is based on three important aspects- hue, tone and saturation. Hue
is the first impression of the color or the light reflected back to the eye,
tone refers to the lightness or darkness of the color and tone determines the
strength of color. For gemstones like ruby, emerald and sapphire darker the
color the better it is and vivid color saturations are preferred. On the other
hand stones like aquamarine are known for their light hues. Showing an absolute
contrast diamonds are colorless and this is the most important virtue which
makes it breath taking.
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| HUE |
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| TONE |
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| SATURATION |
Cut:
cut can be defined as art of shaping the rough gemstones in precise angles and
proportions to bring out the fire in them. The cut describes how a gemstone is
fashioned and its shape. The more accurate and proportionate the cut, greater
is the beauty of the stone. A stone can be either facetted or shaped into
cabochons. A facetted stone is cut with flat symmetrical planes called facets
and cabochons are cut to give a stone a smooth domed surface. There are
different types of cuts for facetted stones and cabochons. Facetted stones can be
fashioned with brilliant cut, step cut or mixed cut. The cut is chosen for a
gem depending on what will bring out its beauty the best. For example a
sapphire will be mostly cut as a facetted stone and gems like coral are usually
fashioned as cabochons.
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| CUTTING STYLES |
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| CABOCHON |
Clarity:
clarity of a gemstone is dependent on the presence of inclusions. An inclusion
can be defined as a material trapped inside the stone or an internal stress
fracture or growth marks. These inclusions have a great bearing on the
transparency of a stone and hence on its beauty. In some stones inclusions add
to the beauty of a stone, like star sapphires. But inclusions can also have a
negative impact on the stone if it is very prominent.
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| INCLUSIONS |
Phenomenon:
many gems display optical phenomenon which not only add to their beauty but
also make the gem very rare and unique. There is a variety of phenomena
displayed by gems. For example moonstone displays the phenomenon of
adularescence and opals display play of colors. Likewise there are other
phenomena like chatoyancy, color change, aventurescence, asterism, iridescence
etc. these optical characteristics of certain gemstones add to the overall
appeal and beauty of the gemstone.
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| IRRIDESCENCE |
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| ADULARESCENCE |
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| ASTERISM |
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| PLAY OF COLOR |
Rarity: Rarity of a gemstone
makes it highly desirable. Rarer the gem higher is the value commanded by it. Rarity
of a gem is related to its formation process. For example certain gems like
garnets are formed more commonly than rubies. Other factors which govern the
rarity of a stone are a rare color in a species, like red beryl is a rare
stone. Emeralds with no or few inclusions with vivid color are very rare.
Similarly, cat’s eye alexandrite displays color change as well which is again
very rare.
Durability: It
can be defined as a vital virtue of a gem which allows it to pass from
generations to generations. In other words durability is the ability of a
gemstone to resist wear and tear. Durability of a stone is dependent upon its crystal
structure. For example, the hardest known gem to mankind is diamond which
belongs to cubic crystal structure which is highly symmetrical.
Gemstones
have a special allure. They always manage to draw appreciation and admiration. They
are not only objects of adornment but treasures which epitomise various
shades of a human’s life. So add color to your life with gemstones!!
*The Author is a Colored Stone Graduate from Gemological Institute of
America, Mumbai and a Diamond Graduate from Solitaire Diamond Institute,
Bangalore. She also holds a Diploma in Jewelry Designing & Manufacturing
from Jewelry Product Development Centre, Jaipur. She also blogs at 'The Jewel Affair'.
** Picture coutesy: Google Images
