Origin of name
This rare and unique black diamond gets it's name from de
Grisogono the famous Swiss jeweler and cutter of diamonds, who together with
Fawaz Gruosi another famous Swiss jeweler had been responsible for creating
the current enthusiasm for black diamond jewelry.
Characteristics of the
diamond
The diamond is a 312.24-carat, old Moghul-cut, black
facetted stone, and it is the largest black diamond and perhaps the 5th
largest facetted diamond in the world.
History
The original rough diamond weighed 587 carats and was
mined in the Central African Republic. Other details of the diamond such as
the date of discovery, the mine of discovery, original owners of the diamond
etc. are not known.
The massive black rough stone arrived in Switzerland
after it's purchase by Fawaz Gruosi, the famous Swiss jeweler. The diamond
was cut by the world renowned black diamond cutting specialist, de Grisogono,
in whose name the diamond was subsequently named. De Grisogono was also
responsible for the cutting of the heart-shaped Gruosi diamond in 1998,
another black diamond owned by Fawaz Gruosi.
The cut employed on the stone was a modified old Moghul-cut,
an appropriate design selected by the experienced cutter, to suit the shape
of the rough stone. The old Moghul-cut can be seen in many of the historic
diamonds that originated in India, during the Moghul period, such as the
Orlov diamond, the Taj-i-Mah diamond, and a number of diamonds in the
Iranian Crown Jewels. The planning of the cutting and the actual cutting
process took more than one year. This is not surprising because black
diamonds are usually extremely hard and difficult to cut and polish. the
stone has been mounted on a white gold ring, set with 702 white diamonds
totaling 36.69 carats as shown in the photograph.
The following is a list
of some of the world famous black diamonds :-
|
S/N |
Name |
carat weight |
shape/cut |
|
1 |
The Spirit of Grisogono |
312.24 |
old moghul-cut |
|
2 |
The Gruosi diamond |
115.34 |
heart-shaped |
|
3 |
The Black Orlov |
67.00 |
cushion-cut |
|
4 |
The Amsterdam |
33.74 |
pear-shaped |
Black diamonds, also known as Carbonodo have along been a
puzzle for Geologists. There has been a controversy about the origin
and the distribution of naturally occurring black diamonds in the world
today. A comparison of the characteristics of black diamonds as against
conventional diamonds can be very informative and interesting.
|
|
Black Diamonds |
Conventional Diamonds |
|
1 |
Black diamonds are porous, like pumice formed from
larva of volcanoes. They appear to be composed of millions of minute
diamond crystals stuck together.
|
Conventional diamonds are non-porous and exist as
large crystals, with a classic crystal structure
|
|
2
|
The porous material is full of bubbles that appear to
result from gases present when the diamonds were formed
|
Conventional diamonds were formed deep within the
earth's crust where the high pressure does not allow gases to exist
|
|
3
|
Black diamonds are found in alluvial deposits, and
never found in Kimberlite pipes, indicating that black diamonds were not
formed inside the earth's crust.
|
Conventional diamonds are found in Kimberlite and
lamproite pipes as well as alluvial deposits which indicate they were
formed deep inside the earth's crust, and later brought up to the
surface.
|
|
4 |
Black diamond are extremely hard and difficult to cut
and polish. The hardness of black diamonds exceeds that of
conventional diamonds
|
Conventional diamonds are the hardest substances
known, but they are less hard than the harder black diamonds.
|
|
5 |
The extreme hardness of black diamonds is attributed
to lack of crystal planes along which cleavage can occur.
|
Conventional diamonds cleave along crystal planes
|
|
6 |
Black diamond are more suitable for industrial uses
such as grinding and drilling and less suitable for ornamental
purposes.
|
Conventional diamonds are more suitable for ornamental
purposes.
|
Today the only important sources of black diamonds in the
world are Brazil and Central African Republic. Not one black diamond has
ever been produced in the conventional diamond mines of South Africa,
Russia, Australia and Canada, the main sources of the approximately 600 tons
of conventional diamonds produced in the last century. The two main black
diamond locations in the world are isolated and separate from the
conventional diamond locations. This coupled with the fact that black
diamonds are only found as alluvial deposits has given rise to the
speculation that black diamonds came from outer space, and have a
extra-terrestrial origin. A team of Geologists from the Florida
International University, has proposed that an asteroid of about half a mile
in diameter impacted the earth billions of years ago, when South-America and
Africa were once connected land masses. The deposit of black diamonds are
today thousands of miles apart because of the continental drift, that
occurred afterwards.
The possible stellar origins of black diamonds, may in
the future become a marketing theme to popularize black diamond jewelry, as
diamond shoppers would no doubt be interested in owning a diamond that
originated in outer space.
