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Most of us know diamonds as diamonds in jewelry such as wedding rings,
diamond earrings, diamond engagement rings, diamond anniversary rings,
diamond solitaire rings and 3 stone rings etc. However, diamonds are
used for multiple purposes. You will find the following information
interesting. Read on..
Natural Diamonds
Natural Diamonds vary depending on their formation process, the kind of
inclusions that occur during their formation, creates variations in
terms of color and electrical conductivity.
Diamond is composed of the
single element carbon, and it is the arrangement of the C atoms in the
lattice that give diamond its amazing properties. Compare the structure
of diamond and graphite, both composed of just carbon. In diamond we
have the hardest known material, in graphite we have one of the softest,
simply by rearranging the way the atoms are bonded together.
Type I Diamonds:
This is the most commonly occurring form of natural diamond. They are
further classified into type Ia and Ib.
Type
Ia:
These diamonds contain about 0.3% nitrogen. Nitrogen absorbs blue light
so they have a pale yellow or brown color. About 98% of diamonds come
under this category.
Type
Ib:
When Nitrogen atoms get uniformly distributed all over in diamond’s
crystal structure, the overall structure thus formed absorbs green and
blue parts of the spectrum. This results in a darker appearance,
generally deep yellow, brown, even greenish, canary and orange. These
diamonds are very rarely found. About 0.1% belongs to this category.
Synthetically produced diamonds are mostly found to be Type1b which
contain about 500ppm of nitrogen impurity.
Type II:
These diamonds include very few nitrogen atoms such that the number is
insignificant. So the crystal structure has fewer inclusions and this
results in a more pure carbon crystal. The presence of nitrogen atoms is
difficult to be detected even by Infrared and UV absorption methods.
Type II diamonds are rarely found in nature.
Type
IIa:
Type IIa diamonds are almost colorless, and have a slight yellowish tint
due to the presence of twisted carbon tetrahedrons that were formed
while diamond was being transported to the earth’s surface. The twisted
structures absorb some part of the light and thus result in yellow,
brown and sometimes pink and red colors.
Type
IIb:
Boron is the impurity found in these diamonds instead of Nitrogen. Boron
is known to absorb yellow, orange and red parts of the spectrum, which
results in appearance of blue color in these diamonds. But they can also
be grayish and sometimes almost colorless. These diamonds are very
rarely found.
Green Diamonds:
In their raw and uncut forms, green diamonds are yellowish green
characterized by the degree of lubricity. These diamonds show their
green color after being cut. The famous collection of De Beers Fancy
colored diamonds includes some of the world’s most beautiful and rare
green diamonds.
The color of these diamonds
results from being in contact with a radioactive source before being
mined at some point of its lifetime under the earth. Prolonged exposure
to beta, gamma rays as well as neutron particles present in uranium
compounds is believed to be the cause.
The color of these stones is
sometimes treated by heating but care is taken to keep the temperature
below 600 degrees Celsius, otherwise there are chances of modification
of the gem’s crystal lattice to give a yellow or brown color to the
treated gem. After a treatment the gem’s crystal lattice remains
permanently distorted.
These diamonds are generally
found in alluvial deposits and also found in upper parts of diamond
bearing volcanic “pipe". The most famous green diamond is Dresden Green.
Synthetic Industrial
Diamonds
Synthetic industrial diamonds are produced by the process of High
Pressure High Temperature Synthesis (HPHT). In HPHT synthesis, graphite
and a metallic catalyst are placed in a hydraulic press under high
temperatures and pressures. Over the period of a few hours the graphite
gets converted to diamond. The resulting diamonds are usually a few
millimeters in size and include a number of flaws which make them unfit
for use as gemstones, but they are extremely useful for industrial
purposes, e.g. edges on cutting tools, drill-bits and for being
compressed to generate very high pressures. (Although used to cut,
grind, and polish many materials, diamonds aren't used to machine alloys
of iron because the diamond (carbon) reacts with iron at high
temperatures).
Thin Film Diamonds
Chemical Vapor Deposition (CVD) process is used to deposit thin films of
polycrystalline diamond. CVD technology makes it possible to put
'zero-wear' coatings on machine parts. Diamond coatings are used to draw
the heat away from electronic components, fashion windows that are
transparent over a broad wavelength range, and take advantage of other
properties of diamonds.
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 well it is cut. 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........
Read more...
Diamond Fluorescence
Fluorescence is the emission of bluish light emitted by about one third
of gem-quality diamonds when exposed to long-wave ultraviolet light. The
intensity may vary from faint to very strong. Under normal lighting conditions,
this property of fluorescence is not detectable. However, a naturally
fluorescent diamond tends to emit a soft colored glow when held under an
ultraviolet lamp or “black light". Fluorescence is not harmful to the diamond or
to the wearer......
Read more...
Read More about Diamonds
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....
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