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Structure of Diamond
Everyone knows diamonds are hard
and beautiful, but did you know a diamond could be the oldest material you
might own? While the rock in which diamonds are found may be 50 to 1,600
million years old, the diamonds themselves are approximately 3.3 billion
years old. This discrepancy is because the volcanic magma that solidifies
into rock where diamonds are found did not create them, but only transported
the diamonds from the Earth's mantle to the surface.
Diamonds also may be formed under
the high pressures and temperatures at the site of meteorite impacts. The
diamonds formed during an impact may be relatively 'young', but some
meteorites contain star dust, debris from the death of a star, which may
include diamond crystals. One such meteorite is known to contain tiny
diamonds over 5 billion years old.
These diamonds are older than
our solar system!
Early Experiments with Diamond
The ancients had no suspicion of
the true nature of the diamond. To have any idea of this subject, it was
necessary that the bases of modern chemistry should be established, or at
least that the complex phenomenon of combustion should have received its
true explanation. Newton suspected from its wonderful refractive power that
the diamond was combustible, but even as late as the middle of the
eighteenth century, the definition of its composition, given in a standard
work on physics, was--"the purest and finest earth, the most ethereal fire,
and the most limpid water."
The first important fact relative
to the nature of the diamond was established by Boyle about the middle of
the seventeenth century. He showed that under the influence of a great heat
the diamond disappeared. A little later, in 1694, Cosmo III., Grand-duke of
Tuscany, had a diamond subjected at Florence to the intense heat of the
sun's rays, by aid of a concave mirror. The experiment was conducted by
Averini, preceptor of the Prince John Gaston, son of Cosmo, and Targioni,
member of the Academy del Cimento. The diamond first split, then emitted
sparks, and finally disappeared.
Structure of a Faceted Diamond
The natural beauty of a diamond
is enhanced by how it is cut because the fluorescence, light dispersion etc.
depends on how ell it is cut. Diamond cutting has almost become a science
and each of the diamond facet is critical to how beautiful and attractive it
would look after it is faceted. If you want to know more about diamonds, or
especially if you want to study diamonds as a gem, it is useful to know the
important facets of a diamond such as table, pavilion, girdle, crown etc.
The widest part of any round
diamond, the part in the middle, is known as the girdle, which is probably
quite self explanatory. The top part, above the girdle is known as the
crown, and the lower part below the girdle is known as the pavilion. The
point or small facet at the very bottom is known as the culet. Each flat
face of the diamond is known as a facet, and each type of facet has its own
name. Read more information about these facets below.
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Table
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The flat facet on the top of the diamond. It is the largest facet on
a cut diamond. |
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Crown |
The upper part of the diamond above the girdle. Consists of a large
flat area on top called a table, and several facets below it. |
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Girdle |
The outer edge or the widest part of the diamond forming a band
around the stone |
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Diameter |
The width of the diamond as measured through the girdle. |
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Depth |
The height of a diamond from the culet to the table. The depth is
measured in millimeters. |
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Pavilion |
The bottom part of the Diamond, below the girdle. |
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Cutlet |
A tiny flat facet that diamond cutters sometimes add at the bottom
of a diamond's pavilion. Its purpose is to protect the tip of the
pavilion from being chipped or damaged. Once a diamond is set in
jewelry, though, the setting itself generally provides the pavilion
with sufficient protection from impact or wear. Large or extremely
large culets were common in diamonds cut in the early part of this
century, such as the Old European or Old Mine Cut. However, such
large culets are rarely seen today. Most modern shapes have either
no culet at all, or a small or very small culet. |
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Crown Angle |
The angle at which a diamond's bezel facets intersect the girdle
plane. This gentle slope of the facets that surround the table is
what helps to create the dispersion, or fire, in a diamond. White
light entering at the different angles in broken up into its
spectral hues, creating a beautiful play of color inside the
diamond. The crown angle also helps to enhance the brilliance of a
diamond. |
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Reflection |
A diamond’s reflection highly depends on its quality of polish and
cleanliness.
Light can be reflected from the surface of the facets directly or
after entering the diamond. The amount of light reflected by a
material is determined by the refractive index and diamond exhibits
maximum reflectance among all transparent materials. Diamond
therefore exhibits excellent reflection of light depending on the
cut type. Different cuts show different amount of reflection,
refraction and dispersion. |
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Refraction |
Diamond’s great ability to refract light makes it lustrous and
brilliant in appearance. The light entering a diamond gets bent at
certain angles, depending on the cut, and slowed down due to
material properties and comes out after getting reflected from
different angles and facets. Here cut quality and type both play an
important part. Light traveling
through a stone intersects the stone-air surface. If it passes
within the critical angle (measured relative to the normal to that
surface), it will exit the stone. If it passes outside the critical
angle, it will be internally reflected. |
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Dispersion |
Another most prized attribute of a diamond as a gemstone, is its
ability to disperse light into the seven colors of spectrum. The
“fire" and the glitter of the gem is because of this amazing ability
that has made diamond unique and precious among other gemstones.
Greater the dispersion, greater is the distance between the
dispersed colors, which can make the colors vivid and easy to
distinguish. The refractive index of a material varies with the
wavelength. It means short wavelengths (Violet and Blue colors) are
bent more as compared to longer (Yellow and Red colors) ones. The
coefficient of dispersion judges this variation in the angles for
different wavelengths, the greater the coefficient, the greater is
the angular spread of different colors of white light falling at a
certain angle on the material. The dispersion of light decides the
gem’s fire. |
Diamond Cut
A diamond cut is considered to be the most important
characteristic for judging diamond quality. Even if the
mined diamond has good clarity and desired color, the
cut determines the overall look and feel of the gem.
Cutting a diamond works like making finished product
(gemstone) out of raw material (the mined diamond). A
cut refers to symmetry...
Read
about Diamond History, Diamond Facts and More......
A symbol of innocence,
justice, faith and strength, the diamond was believed to make its
wearers courageous and victorious over their enemies. When set in gold
and worn on the left side, it held the power to drive away nightmares
and soothe savage beasts. Diamonds were even thought to be so powerful
that they could stop lechery.
Diamonds have lured and
fascinated us for centuries. Their ores and lore recorded romantic and
bloody events in the past. Diamonds have been long cherished and sought
after, fought over and killed for in the human history simply because of
its beauty and the fascination....
Back to Diamond
Information Summary...
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Structure of Diamond
